EXHIBIT 10.1 ASSET TRANSFER AGREEMENT AMC, UE AND

THIS ASSET TRANSFER AGREEMENT (this “Agreement”) dated as of May 2, 2005, by and among Union Electric Company d/b/a AmerenUE, a Missouri corporation (“Transferor”), Central Illinois Public Service Company d/b/a AmerenCIPS, an Illinois corporation (“Transferee”), and Ameren Corporation, a Missouri corporation (“Parent”).

WHEREAS, Parent owns 100% of the common stock of each of Transferor and Transferee; and

WHEREAS, Transferor is a public utility company as defined in Section 3-105 of the Illinois Public Utilities Act (220 ILCS 5/3-105) and is a public utility as defined in Section 386.020 of the Missouri Public Service Commission Law (§386.020 RSMo 2000) and presently operates as a vertically integrated electric generation, transmission and distribution company and as a natural gas distribution company in the States of Illinois and Missouri; and

WHEREAS, Transferor owns and operates electric transmission and distribution facilities and natural gas distribution facilities located in the State of Illinois, which Facilities (as hereinafter defined) are more fully described in Sections 1.1(c) and 1.1(d) hereof, for use in its business of transmitting and distributing electricity and gas (the “Business”); and

WHEREAS, Transferor desires to transfer to (1) Parent, by way of an in kind dividend, a portion of, and (2) to Transferee, the remaining portion of, substantially all of its assets, properties, rights and interests that are used in or related to the Business that is conducted at the Facilities and located in the State of Illinois; and

WHEREAS, Parent desires to contribute that portion of the Business and Facilities received by it to Transferee and Transferee desires to accept from Parent and acquire from Transferor, upon the terms and subject to the conditions hereinafter set forth, in the aggregate substantially all of such assets, properties, rights and interests of Transferor that are used in or related to the Business that is conducted at the Facilities; and

WHEREAS, Transferee desires to execute and deliver to Transferor a subordinated promissory note in exchange for that portion of the Facilities and Business transferred directly to Transferee from Transferor.

NOW, THEREFORE, in consideration of the premises and the mutual covenants hereinafter contained and other good and valuable consideration had and received, Parent, Transferee and Transferor, on the basis of, and in reliance upon, the representations, warranties, covenants, obligations and agreements set forth in this Agreement, and upon the terms and subject to the conditions contained herein, hereby agree as follows:

1.1    Identification of Assets . Immediately prior to the Closing (as defined in Section 4.1), Transferor shall identify in reasonable detail all of the assets, properties, rights and interests owned, used, occupied or held by or for the benefit of Transferor that are used in or related to the operation of the Business at the Facilities, as the same are expected to exist as of the Closing Date (as defined in Section 4.1) and as shall be more fully described in a schedule to be delivered by Transferor to Parent and Transferee or its authorized representatives at the Closing (the “Schedule”), which Schedule shall specifically enumerate such assets, properties and rights, including, without limitation, the following:

(a)    Inventory . All inventory, including inventories of products, work-in-process, finished goods, raw materials, natural gas storage, fuel stock, fuel supplies and parts, which is located at the Facilities and used in the Business (collectively, “Inventory”);

(b)    Fixed Assets . All tangible personal property, plant and equipment including, without limitation, buildings, structures, substations, transmission lines, distribution facilities, pipelines, fixtures, machinery and equipment, maintenance machinery and equipment, vehicles and rolling stock, office furniture and office equipment, other furnishings, leasehold improvements and construction-in-process, which is located at the Facilities and used in the Business, including without limitation plant materials and operating supplies located at the Alton storeroom and truck stock recorded in Account (as defined in Section 12.11) 154 (collectively, the “Fixed Assets”);

(c)    Real Property . (i) The real property rights and interests owned by Transferor and used in or relating to the operation of the Business in the State of Illinois, (ii) any easements, rights of way or other interests in real property necessary for the operation of the Business in Illinois, (iii) all buildings, structures, and leasehold improvements located at the Facilities and all appurtenances relating thereto, and (iv) all fixtures, machinery, apparatus or equipment affixed to said Facilities, including, without limitation, all of the electrical, heating, plumbing, air conditioning, air compression and all other systems located on said premises, and all other structures, fences and improvements (collectively, the “Real Property”);

(d)    Leased Property . All rights and interests under the lease or license agreements (the “Lease Agreements”) that relate to the Business that is conducted in the State of Illinois (the premises subject to the Lease Agreements being hereinafter collectively referred to as the “Leased Property” and the premises that comprise the Leased Property and the Real Property being hereinafter collectively referred to as the “Facilities” or the “Property”; provided, however, that in no event shall “Facilities” or “Property” be deemed to include any rights or interests outside the State of Illinois);

(e)    Intellectual Property Rights . Any and all intellectual property owned or possessed by Transferor and relating to the Business that is conducted at the Facilities including without limitation, copyrights, trade secrets, trademarks and patents;

(f)    Business Records . All books and records that relate to the Business that is conducted at the Facilities, including, without limitation, all files, invoices, forms, accounts,

(g)    Contracts . Subject to Sections 1.4(b) and 1.5, all rights, benefits and interests of Transferor in and to all licenses, leases, contracts, agreements, commitments and undertakings relating to the Business that is conducted at the Facilities (collectively, the “Contracts”);

(h)    Permits . All licenses, permits, approvals, variances, waivers or consents (collectively, the “Permits”), to the extent transferable, issued by any foreign, United States, state or local governmental entity or municipality or subdivision thereof or any authority, department, commission, board, bureau, agency, court or instrumentality (collectively, “Governmental Authorities”) and used in or necessary to the operation of the Business that is conducted at the Facilities;

(i)    Insurance . All rights, claims and benefits of Transferor in, to or under all insurance policies maintained by Transferor for the Business that is conducted at the Facilities or for the Acquired Assets;

(j)    Rolling Stock and Vehicles . All vehicles and rolling stock used in the Business that is conduced at the Facilities and that is included as part of Fixed Assets;

(k)    Petty Cash . All petty cash maintained at the East St. Louis, Illinois office of Transferor (the “Petty Cash”);

(l)    Accounts Receivable . All accounts receivable of Illinois electric and gas customers recorded in Account 142 (the “Accounts Receivable”);

(m)    Uncollectible Accounts . The provision for uncollectible accounts associated with the Accounts Receivable;

(n)    Accrued Revenues . Accrued Illinois electric and gas revenues for services not billed at the time of the transfer contemplated hereby, which are recorded in Account 173;

(o)    Environmental Cleanup . Amounts collected for environmental cleanup that are recorded in Account 186; and

(p)    Customer Deposits . Customer deposits related to Illinois electric customers that are recorded in Account 235.

(q)    Miscellaneous . Except for the Retained Assets (as defined in Section 1.4), all other assets, properties, rights and interests of Transferor otherwise employed in or related to the operation of the Business at the Facilities, of every kind, nature and description, whether

All of the assets, properties, rights and interests owned, used, occupied or held by or for the benefit of the Transferor in the operation of the Business at the Facilities, which are to be dividended, sold, transferred, conveyed, assigned and delivered by Transferor at the Closing as contemplated herein, including without limitation, those described in clauses (a) through (q) above, but excluding the Retained Assets, are referred to herein collectively as the “Acquired Assets.”

1.2    Dividend and Transfer of Assets . At the Closing, Transferor shall:

(a)    transfer, convey, assign and deliver and pay to Parent by way of an in kind dividend on its common stock, declared pursuant to a duly adopted resolution of its Board of Directors, of that portion of the Acquired Assets designated on the Schedule as subject to such dividend (the “Dividend Assets”); and

(b)    transfer, convey, assign, contribute and deliver to Transferee that portion of the Acquired Assets designated on the Schedule as subject to such transfer (the “Transferred Assets”).

The Dividend Assets and the Transferred Assets shall, in the aggregate, consist of all the Acquired Assets. The parties agree that the Dividend Assets will constitute a percentage, based on book value, of all the Acquired Assets and the Transferred Assets will constitute all of the remainder of the Acquired Assets. The percentage of Dividend Assets will be determined by Parent immediately prior to the Closing.

1.3    Contribution of Assets . At the Closing, immediately after receipt of the Dividend Assets pursuant to Transferor’s dividend referred to in Section 1.2 hereof, Parent shall transfer, convey, assign, and deliver to Transferee by way of a contribution to capital all of the Dividend Assets.

1.4    Retained Assets . Anything in Sections 1.1 through 1.3 to the contrary notwithstanding, the following assets (collectively, the “Retained Assets”) shall be retained by Transferor, and neither Parent nor Transferee shall in any way be construed to have acquired (or to be obligated to acquire) any interest whatsoever in any of the following, any of which may be more particularly described on the Schedule:

(a)    Designated Assets . Any of the assets, properties, rights and/or interests, owned, used, occupied or held by or for the benefit of Transferor in the operation of the Business (other than the operation of the Business at the Facilities); provided, however, that anything in this Agreement to the contrary notwithstanding, the Retained Assets shall include the Venice and Keokuk electric generating plants and associated electric transmission facilities, together with minor amounts of miscellaneous property to ensure the smooth operation of Transferor’s electric system;

(b)    Non-Assigned Contracts . All of the rights and interests, and all of the liabilities and obligations, of Transferor in, under or pursuant to any license, lease, contract, agreement, commitment or undertaking entered into in connection with, or otherwise relating to, the operation of the Business (other than the operation of the Business at the Facilities) (collectively, the “Non-Assigned Contracts”);

(c)    Employee Plan Assets . The rights of Transferor or Parent under, and any funds and property held in trust or any other funding vehicle pursuant to, any “employee benefit plan” (within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended) or any other bonus, stock option, stock appreciation, stock purchase, severance, termination, lay-off, leave of absence, disability, workers’ compensation, pension, profit sharing, retirement, vacation or holiday pay, insurance, deferred compensation or other employee or welfare benefit plan, agreement or arrangement of Transferor or Parent applicable to past, present or future employees employed in connection with the Business (collectively, “Employee Plans”);

(d)    Corporate Records . Transferor’s minute books, stock books, stock ledger and corporate seal and all other books and records relating to the Business of the Transferor;

(e)    This Agreement . All of Transferor’s rights, claims and interests under this Agreement and any agreement executed in connection herewith;

(f)    Third Party Actions . All of Transferor’s rights, claims or causes of action against third parties relating to the assets, properties, business or operations of the Business that is conducted at the Facilities to the extent such rights, claims or causes of action arise in connection with the discharge by Transferor of the Retained Liabilities (as defined in Section 2.2);

(g)    Subsidiaries . The capital stock of any of Transferor’s direct or indirect, wholly or partially owned, subsidiaries and their respective assets, properties and businesses;

(h)    Cash and Cash Equivalents . Except for the Petty Cash, any cash or cash equivalent of, owned, or held by, Transferor;

(i)    Discontinued Operations . All assets, properties, rights and interests in, under or to agreements, instruments or contracts relating to businesses, operations or assets that immediately prior to the Closing have been (i) closed, wound up or otherwise terminated or (ii) ceased to be held or used in connection with Transferor’s businesses or operations, including the Business that is conducted at the Facilities; and

(j)    Miscellaneous . Those other certain assets, properties, rights and interests described on the Schedule.

1.5    Assignability and Consents .

(a)    Required Consents . Transferor shall deliver to Parent and Transferee or their authorized representatives, at or prior to the Closing, a list of (i) Acquired Assets, including Contracts, Permits and Lease Agreements (but excluding leases of office equipment involving

future payments of less than $500,000 in the aggregate), that are non-assignable or non-transferable or cannot be subleased to Transferee without the consent of some other individual, partnership, corporation, association, joint stock company, trust, joint venture, limited liability company or Governmental Authority (collectively, “Person”) and (ii) approvals of Governmental Authorities, including the Illinois Commerce Commission (the “ICC”) , the Missouri Public Service Commission, the Federal Energy Regulatory Commission, the Securities and Exchange Commission and the Federal Communications Commission that are required for the consummation of the transactions contemplated by this Agreement. Transferor has commenced and shall continue to take, or cause to be taken by others, all necessary actions required to obtain or satisfy, at the earliest practicable date, all consents, novations, approvals, authorizations, requirements (including filing and registration requirements), waivers and agreements (“Consents”) from any Persons necessary to authorize, approve or permit the full and complete conveyance, assignment, sublease or transfer of the Acquired Assets, and to consummate and make effective the transactions contemplated by this Agreement and to continue such efforts as may be required after the Closing Date to facilitate the full and expeditious transfer of legal title, or the sublease, as the case may be, of the Acquired Assets.

(b)    Nonassignable Items . Anything in this Agreement to the contrary notwithstanding, this Agreement shall not constitute an Agreement to sell, convey, assign, sublease or transfer any Acquired Assets, including Contracts, Permits and Lease Agreements, if an attempted conveyance, assignment, sublease or transfer thereof, without the Consent of another party thereto or a Governmental Authority would constitute a breach of, or in any way affect the rights of Transferor or Transferee with respect to such Acquired Asset (“Nonassignable Items”). Transferor shall use its best efforts and Transferee shall cooperate in all reasonable respects with Transferor to obtain and satisfy all Consents and to resolve all impracticalities of conveyance, assignment, sublease or transfer necessary to convey to Transferee all Nonassignable Items.

2.1    Assumption of Liabilities . On the terms and subject to the conditions set forth in this Agreement, Transferee shall assume, at the Closing and effective as of the Closing Date, and shall thereafter pay, perform and discharge as and when due the following, and only the following, liabilities and obligations of Transferor (collectively, the “Assumed Liabilities”):

(a)    Balance Sheet . All liabilities and obligations of Transferor as set forth on the unaudited balance sheet (the “Balance Sheet”) relating to the Business that is conducted at the Facilities prepared by Transferor as of the Closing or other appropriate date determined by the parties (the “Balance Sheet Date”), including without limitation any indebtedness to be assumed by Transferee (the “Assumed Indebtedness”), less payments thereon or discharges thereof prior to the Closing Date;

(b)    Trade Payables . All liabilities and obligations of Transferor relating to the Business that is conducted at the Facilities that constitute trade payables due to suppliers as payment for Inventory included in the Acquired Assets and incurred by Transferor in the ordinary

(c)    Contracts . All liabilities and obligations of Transferor arising under the terms of the Contracts other than contracts that constitute Non-Assigned Contracts but only to the extent such liabilities and obligations arise or accrue after the Closing Date in the ordinary and normal course and consistent with the representations, warranties, covenants, obligations and agreements set forth in this Agreement; provided, however, that Transferee shall not assume or be responsible for any such liabilities or obligations which arise from breaches thereof or defaults thereunder by Transferor, all of which liabilities and obligations shall constitute Retained Liabilities;

(d)    Liabilities and Obligations . All liabilities and obligations of Transferor relating to environmental permits, variances or orders issued by local, state or federal governmental authorities that relate to the Business that is conducted at the Facilities;

(e)    Litigation . All liabilities and obligations relating to any litigation, action, suit, claim, notice of violation, investigation, inquiry or proceeding (collectively “Claims”) instituted hereafter, based in whole or in part on events or conditions occurring or existing in connection with, or arising out of, or otherwise relating to, the Business that is conducted at the Facilities as operated by Transferee or any of its Affiliates (as defined in Section 12.11) (or any of their respective predecessors-in-interest) after the date hereof, or the ownership, possession, use, operation, sale or other disposition after the Closing Date of any of the Acquired Assets (or any other assets, properties, rights or interests associated, at any time after the Closing Date, with the Business that is conducted at the Facilities); and

(f)    Environmental Liabilities . All liabilities and obligations relating to the Business or the Acquired Assets (or any other assets, properties, rights or interests associated, at any time after the Closing Date, with the Business or the Acquired Assets), based in whole or in part on events or conditions occurring or existing after the Closing Date and connected with, arising out of or relating to Hazardous Materials, Environmental Requirements or Environmental Damages (all as defined in Section 5.1(e)), (the “Assumed Environmental Liabilities”); provided, however, that the Assumed Environmental Liabilities shall also include (i) the environmental cleanup liability at the Alton Town Gas Site that is recorded in Account 253 and (ii) any liabilities and obligations relating to the Business or the Acquired Assets (or any other assets, properties, rights or interests associated, at any time prior to the Closing Date, with the Business or the Acquired Assets), based in whole or in part on events or conditions occurring or existing prior to the Closing Date and connected with, arising out of or relating to Hazardous Materials, Environmental Requirements or Environmental Damages, if and to the extent that such liabilities and obligations are covered by Transferor’s existing ICC-approved electric and gas environmental adjustment clause riders in effect immediately prior to the Closing.

(g)    Accounts Payable . Accounts payable for the amount of natural gas purchased for resale but not yet paid that are recorded in Account 232.

(h)    Accrued Payroll . Accrued payroll payables that are recorded in Account 232.

(i)    Vacation Liability . Accrued vacation liabilities for electric and gas employees that are recorded in Account 242.

(j)    Customer Liabilities . All liabilities and obligations relating to the Business or the Acquired Assets (or any other assets, properties, rights or interests associated, at any time prior to or following the Closing Date, with the Business or the Acquired Assets), based in whole or in part on events or conditions occurring or existing prior to or following the Closing Date and connected with, arising out of or relating to any disputes for services rendered or goods manufactured that are instituted or maintained by or in the right of any customer, including without limitation, product warranty Claims and product liability Claims, and Claims for refunds, returns, personal injury and property damages.

(k)    Taxes . All liabilities and obligations relating to the Business or the Acquired Assets (or any other assets, properties, rights or interests associated, at any time prior to or following the Closing Date, with the Business or the Acquired Assets), whether due or becoming due and whether based on or arising out of events prior or subsequent to the Closing Date, relating to the payment of franchise fees, gross receipts or utility Taxes (as hereinafter defined) of any kind (the “Assumed Tax Liabilities”).

2.2    Retained Liabilities . Except to the extent transferred to Transferee as an Assumed Liability pursuant to Section 2.1, including without limitation with respect to Assumed Environmental Liabilities, Transferor shall retain, and Transferee shall not assume, or be responsible for or liable with respect to, any liabilities or obligations of, Transferor, or otherwise relating to the Business, whether or not of, associated with, or arising from, any of the Acquired Assets, and whether fixed, contingent or otherwise, known or unknown (collectively referred to hereinafter as the “Retained Liabilities”), including, without limitation, the following:

(a)    Pre-Closing . All liabilities and obligations relating to, based in whole or in part on events or conditions occurring or existing in connection with, or arising out of, the Business as operated prior to the Closing Date, or the ownership, possession, use, operation or other disposition prior to the Closing Date of any of the Acquired Assets (or any other assets, properties, rights or interests associated, at any time prior to the Closing Date, with the Business);

(b)    Liabilities Relating to the Transfer of Acquired Assets . All liabilities and obligations of Transferor or any of its Affiliates except Transferee, or their respective directors, officers, shareholders or agents, arising out of, or relating to, this Agreement or the transactions contemplated hereby, whether incurred prior to, at, or subsequent to the Closing Date;

(c)    Employee-Related Liabilities . All liabilities and obligations to any persons at any time employed by Transferor or its Affiliates except Transferee or their respective predecessors-in-interest in the Business or otherwise, at any time or to any such person’s spouses, children, other dependents or beneficiaries, with respect to incidents, events, exposures or circumstances occurring at any time during the period or periods of any such persons’ employment with Transferor or its Affiliates except Transferee or their respective predecessors-in-interest, whenever such claims mature or are asserted, including, without limitation, all liabilities and obligations arising (i) under any Employee Plans, (ii) under any

(d)    Litigation . All liabilities and obligations relating to any Claims pending on the date hereof, or instituted hereafter, based in whole or in part on events or conditions occurring or existing in connection with, or arising out of, or otherwise relating to, the Business as operated by Transferor or any of its Affiliates (or any of their respective predecessors-in-interest) except Transferee, or the ownership, possession, use, operation, sale or other disposition prior to the Closing Date of any of the Acquired Assets (or any other assets, properties, rights or interests associated, at any time prior to the Closing Date, with the Business);

(e)    Product, Environmental and Safety Liability . All liabilities and obligations relating to the Business or the Acquired Assets (or any other assets, properties, rights or interests associated, at any time prior to the Closing Date, with the Business or the Acquired Assets), based in whole or in part on events or conditions occurring or existing prior to the Closing Date and connected with, arising out of or relating to (i) any dispute for services rendered or goods manufactured, including, without limitation, product warranty Claims and product liability Claims, and Claims for refunds, returns, personal injury and property damage, (ii) Hazardous Materials, Environmental Requirements or Environmental Damages other than liabilities or obligations that constitute Assumed Environmental Liabilities (the “Non-Assumed Environmental Liabilities”), (iii) Claims relating to employee health and safety, including Claims for injury, sickness, disease or death of any Person, or (iv) compliance with any Laws relating to any of the foregoing;

(f)    Taxes . Except for the Assumed Tax Liabilities, all liabilities and obligations of Transferor or any of its Affiliates (or any of their respective predecessors-in-interest) for any Taxes due or becoming due by reason of (i) the conduct of the Business, or (ii) the ownership, possession, use, operation, purchase, acquisition, sale or disposition, of any of the Acquired Assets, including, without limitation, (i) Taxes attributable to the sale of electricity and employee withholding tax obligations; (ii) Taxes imposed on, or accruing as a result of the transfer of the Acquired Assets; and (iii) Taxes attributable to, or resulting from, recapture of depreciation, other tax benefit items, or otherwise arising from the transactions contemplated by this Agreement. For purposes of this Agreement, the term “Tax” or “Taxes” means all net income, gross income, gross receipts, sales, use, ad valorem, personal property, real property, transfer, franchise, profits, license, withholding, payroll, employment, excise, severance, stamp, occupation, premium, property or windfall profits, taxes, customs duties or other taxes, fees, assessments or charges of any kind whatsoever, including without limitation, any assessment which Transferor may have had the option to pay in installment payments over a period of time which extends beyond the Closing Date, together with any interest and any penalties, additions to tax or additional amounts imposed by any taxing authority (domestic or foreign); and

(g)    Liabilities Relating to Retained Assets . All liabilities and obligations relating to, based in whole or in part on events or conditions occurring or existing in connection with, or arising out of, any and all assets, properties, rights and interests which are not being acquired by Transferee hereunder, including, without limitation, the Retained Assets.

3.1    Payment . (i) In full consideration for the transfer of the Transferred Assets, but subject to the adjustment, if any, required by Section 3.2, at the Closing, Transferee shall deliver to Transferor a subordinated promissory note in the form of Exhibit 3.1 hereto (the “Transferee Note”) in an amount equal to the book value of the Transferred Assets determined as provided herein.

(b)    No amount shall be paid to Parent in connection with the contribution by Parent of the Dividend Assets.

3.2    Prorations . (i) Transferor and Transferee shall prorate, as of the Closing Date, all real estate taxes payable with respect to the Real Property (but not including any current assessments against the Real Property which Transferor is required to have paid in full prior to the Closing Date as provided under Section 2.2(f) herein).

(b)    Transferee and Transferor shall use their reasonable best efforts to calculate all prorations. The credit that Transferee is entitled to receive from Transferor for the unpaid portion (as of the Closing Date) of the 2004 real estate taxes shall be referred to herein as the “2004 Real Estate Tax Credit,” and the credit that Transferee is entitled to receive from Transferor for the 2000 real estate taxes owed for the period during which Transferor owned the Real Property during the year 2005 shall be referred to herein as the “2005 Real Estate Tax Credit.”

4.1    General . As used in this Agreement, the “Closing” shall mean the time at which Transferor consummates the assignment, transfer and delivery of the Acquired Assets to Transferee and Parent and Parent consummates the assignment, transfer and delivery of the Dividend Assets to Transferee as provided herein by the execution and delivery by Transferor and Parent of the documents and instruments referred to in Sections 4.2 and 4.4 against delivery by Transferee of the documents and payments provided in Sections 3.1 and 4.3, and delivery by Transferor, Transferee and the other Persons referred to herein of the additional documents referred to in Section 4.5. In the absence of a prior termination of this Agreement by one of the parties in accordance with Article X, the Closing shall take place at the offices of the Parent, One Ameren Plaza, 1901 Chouteau Avenue, St. Louis, Missouri at 8:00 a.m. on May 2, 2005, or at such other time and place and on such other day as shall be mutually agreed upon in writing by the parties hereto (the “Closing Date”). Legal title, equitable title and risk of loss with respect to the Acquired Assets shall not pass to Transferee until the Acquired Assets are transferred at the Closing, which transfer, once it has occurred, shall be