AMENDMENT NO. 4 to the Credit Agreement

AMENDMENT NO. 4 dated as of August 5, 2009 to the Credit Agreement referred to below, among DYNEGY HOLDINGS INC. (the “ Borrower ”), DYNEGY INC., a Delaware corporation, the other Guarantors party to such Credit Agreement, the Lenders party hereto, CITICORP USA, INC. and JPMORGAN CHASE BANK, N.A., as Administrative Agents, CITICORP USA, INC., as Payment Agent, JPMORGAN CHASE BANK, N.A., as Collateral Agent, and each Revolving L/C Issuer.

The Borrower, the Guarantors party thereto, the Lenders, the Agents and the L/C Issuers are parties to a Fifth Amended and Restated Credit Agreement dated as of April 2, 2007 (as amended, supplemented or otherwise modified from time to time, the “ Credit Agreement ”).

The parties hereto hereby agree as follows:

Section 1.   Defined Terms .  Capitalized terms used but not otherwise defined herein have the meanings given them in the Credit Agreement.

Section 2.   Amendments to Credit Agreement .  Subject to the satisfaction of the conditions set forth in Section 4 of this Amendment No. 4, but effective as of the Amendment No. 4 Effective Date (as defined in such Section 4), the Credit Agreement shall be amended as follows:

2.01            Definitions, etc.

A.  Section 1.01 of the Credit Agreement shall be amended by amending the following definitions (to the extent already included in said Section 1.01) and inserting the following definitions in the appropriate alphabetical location (to the extent not already included in said Section 1.01):

“ 1996 Indenture ” means the Indenture dated as of September 26, 1996 between the Borrower and JPMCB (successor to The First National Bank of Chicago and Bank One, N.A.), as trustee, as amended and restated on March 23, 1998 and as further amended and restated on March 14, 2001.

“ 2011 Senior Notes ” means the 6.875% Senior Notes due 2011 issued by the Borrower in an aggregate original principal amount of $500,000,000 under the 1996 Indenture.

“ 2012 Senior Notes ” means the 8.75% Senior Notes due 2012 issued by the Borrower in an aggregate original principal amount of $500,000,000 under the 1996 Indenture.

“ Amendment No. 4 ” means Amendment No. 4 dated as of August 5, 2009 to this Agreement.

“ Amendment No. 4 Effective Date ” means the date as of which Amendment No. 4 shall become effective pursuant to Section 4 thereof.

“ Applicable Margin ” means, for any day, (a) with respect to the Term Loans, (i) 2.75%, in the case of Base Rate Loans and (ii) 3.75%, in the case of Eurodollar Loans and (b) with respect to Revolving Credit Loans of any Type, or with respect to the commitment fees payable hereunder, the applicable rate per annum set forth below under the caption “Revolving Credit Loans”, based upon the ratings by S&P and Moody’s, respectively, applicable on such date to the Revolving Credit Facility (such rate, in the case of the commitment fees payable hereunder, being the “ Applicable Commitment Fee Rate ”):

For purposes of the foregoing, (i) if either Moody’s or S&P shall not have in effect a rating for the Facilities (other than by reason of the circumstances referred to in the penultimate sentence of this definition), then the Applicable Margin and the Applicable Commitment Fee Rate shall be based on Category 2 above; (ii) if the ratings established or deemed to have been established by Moody’s and S&P for the Facilities shall fall within different Categories above, (A) the Applicable Margin and the Applicable Commitment Fee Rate shall be based on the higher of the two ratings in the event that the rating falling within Category 2 is only one rating level below the respective rating for such rating agency that falls within Category 1 and (B) the Applicable Margin and the Applicable Commitment Fee Rate shall be based on the lower of the two ratings in the event that the rating falling within Category 2 is two or more rating levels below the respective rating for such rating agency that falls within Category 1; and (iii) if the ratings established or deemed to have been established by Moody’s and S&P for the Facilities shall be changed (other than as a result of a change in the rating system of Moody’s or S&P), such change shall be effective as of the date on which it is first announced by the applicable rating agency, irrespective of when notice of such change shall have been furnished by the Borrower to the Payment Agent pursuant to Section 6.02(h) or otherwise.  Each change in the Applicable Margin or the Applicable Commitment Fee Rate shall apply during the period commencing on the effective date of such change and ending on the date immediately preceding the effective date of the next such change.  If the rating system of Moody’s or S&P shall change, or if either such rating agency shall cease to be in the business of rating debt obligations of the same type as the Facilities, the Borrower and the Lenders shall negotiate in good faith to amend this definition to reflect such changed rating system or the unavailability of ratings from such rating agency and, pending the effectiveness of any such amendment, the Applicable Margin shall be determined by reference to the rating most recently in effect prior to such change or cessation.  Notwithstanding any other provision of this Agreement, no reduction in the Applicable Margin or the Applicable Commitment Fee Rate shall occur so long as any Event of Default has occurred and is continuing.  For avoidance of doubt, the Applicable Margin with respect to any Base Rate Loan or Eurodollar Rate Loan or the Applicable Commitment Fee Rate, (i) for any day prior to the Amendment No. 4 Effective Date, shall be determined in accordance with the definition of “Applicable Margin” under this Agreement as in effect immediately prior to the Amendment No. 4 Effective Date and (ii) for any day from and after the Amendment No. 4 Effective Date, shall be determined in accordance with this definition (after giving effect to Amendment No. 4).

“ Borrower Group ” means the Borrower and all of its Restricted Subsidiaries.

“ Cash Equivalents ” means:

(a)   Dollars;

(b)   (i) securities issued or directly and fully guaranteed or insured by the United States government or any agency or instrumentality of the United States government ( provided that the full faith and credit of the United States is pledged in support of those securities) and (ii) debt obligations issued by the Government National Mortgage Association, Farm Credit System, Federal Home Loan Banks, Federal Home Loan Mortgage Corporation, Financing Corporation and Resolution Funding Corporation, in each case, having maturities of not more than thirteen months from the date of acquisition;

(c)   certificates of deposit, demand deposits, and time deposits with maturities of not more than thirteen months from the date of acquisition, bankers’ acceptances with maturities of not more than thirteen months from the date of acquisition and overnight bank deposits, in each case, with any Lender or with any domestic branch of a commercial bank having capital and surplus in excess of $500 ,000,000 and whose short-term debt, or whose parent company’s short-term debt, has the highest rating obtainable from Moody’s or S&P;

(d)   repurchase obligations (including under tri-party repurchase agreements) with a term of not more than thirteen months from the date of acquisition for underlying securities of the types described in clauses (b) and (c)  above entered into with any financial institution meeting the qualifications specified in clause (c)  above;

(e)   commercial paper, notes and bonds having one of the two highest ratings obtainable from Moody’s or S&P and in each case maturing within thirteen months from the date of acquisition; and

(f)            money market funds which invest primarily in assets of the kinds described in clauses (a) through (e)  above.

“ Consolidated Senior Secured Indebtedness ” means, as of any date of determination and without duplication, for the Borrower Group on a consolidated basis, the sum (without duplication) of (a) all Total Indebtedness and (b) the aggregate undrawn amount of all outstanding Letters of Credit and all other letters of credit issued for the account of any member of the Borrower Group and the aggregate amount of unreimbursed drawings under the Letters of Credit and/or such letters of credit, in each case under clauses (a) and (b) above, that are secured by a Lien on property of any member of the Borrower Group (other than a Lien expressly ranking junior in priority to any other Lien).  For avoidance of doubt, secured Hedging Obligations and obligations in respect of Swap Contracts shall not be included in Consolidated Senior Secured Indebtedness for purposes of this Agreement.

“ Discontinued Business Operations ” means, with respect to the Borrower and its Restricted Subsidiaries, the results of operations and any charges, fees, penalties, costs or impairments associated with (a) lines of business or assets that were wound down, discontinued, sold, transferred, or otherwise disposed of, or were under contract to be sold, transferred, or otherwise disposed of, by the Borrower or any of its Subsidiaries on or prior to the Amendment No. 4 Effective Date, including those associated with Dynegy Midstream Services, Limited Partnership, Electric Energy Inc., West Coast Power, Dynegy Intrastate Pipeline LLC’s sale of the Breckenridge assets, Hartwell Energy Limited Partnership, Michigan Power Holdings, Inc. and Michigan Power Limited Partnership, the Sherman Gas Processing Plant and related gathering system, Commonwealth Atlantic Limited Partnership, Oyster Creek Limited Partnership, Dynegy Global Liquids, Inc., Northern Natural Gas Company, NNGC Holding Company, Inc., MCTJ Holding Co. LLC, Dynegy Onshore Processing UK Limited, Dynegy Storage Limited, Dynegy Offshore UK Limited, Dynegy Canada Gas Marketing Ltd., the Hackberry LNG Facility, the Indian Basin Plant and the related gathering system and related facilities, IGC Jamaica Partnership, LLC, Plantas Eolicas S. de R.L., Dynegy Communications Clearinghouse, Inc., Calcasieu Power, LLC, Rockingham Power, LLC, CoGen Lyondell, Inc., Heard County Power, L.L.C., Rolling Hills Generating, L.L.C. and their respective Subsidiaries, (b) lines of business or assets that are being wound down, discontinued, sold, transferred, or otherwise disposed of in connection with Third Party Risk Management or those associated with Dynegy Communications or (c) any Tolling Agreement, including the termination, sale, transfer, disposal, or restructuring thereof.

“ Measurement Period ” means, at any date of determination, the most recently completed four fiscal quarters of the Borrower ending on or prior to such date; provided that, for purposes of any calculation made on a pro forma basis or giving pro forma effect to an event, “ Measurement Period ” means, at any date of determination, the most recently completed four fiscal quarters of the Borrower ending on or prior to such date for which internal financial statements are available.

“ Permitted Acquisition ” means any acquisition, by merger or otherwise, by the Borrower or any of its Restricted Subsidiaries of assets or Capital Stock after the Closing Date, so long as, (a) such acquisition and all transactions related thereto shall be consummated in accordance with all Laws; (b) such acquisition shall result in the issuer of such Capital Stock becoming a Restricted Subsidiary and, to the extent required by Section 6.12 , a Borrower Subsidiary Guarantor; (c) such acquisition shall result in the applicable Collateral Trustee, for the benefit of the Secured Parties, being granted a security interest in any Capital Stock and/or any assets so acquired to the extent required by Sections 6.12 and/or 6.13 ; (d) after giving effect to such acquisition, no Default shall have occurred and be continuing; and (e) the Borrower shall be in compliance, on a pro forma basis after giving effect to such acquisition (including any Indebtedness assumed or permitted to exist or incurred pursuant to Sections 7.03(b)(xiii) and 7.03(b)(xiv) , respectively), with the covenants set forth in Section 7.11 , as such covenants are recomputed as if such acquisition had occurred on the first day of the applicable Measurement Period.

“ Permitted Refinancing Indebtedness ” means any Indebtedness of the Borrower or any of its Restricted Subsidiaries issued in exchange for, or the net proceeds of which are used to extend, renew, refund, refinance, replace, defease, or discharge other Indebtedness of the Borrower or any of its Restricted Subsidiaries (other than intercompany Indebtedness) that is permitted pursuant to Section 7.03 ; provided   that:

(a)   the principal amount (or accreted value, if applicable) of such Permitted Refinancing Indebtedness does not exceed the principal amount (or accreted value, if applicable) of the Indebtedness extended, refinanced, renewed, replaced, defeased, refunded or discharged (plus all accrued interest on the Indebtedness and the amount of all expenses and premiums incurred in connection therewith);

(b)   such Permitted Refinancing Indebtedness has a final maturity date later than the final maturity date of, and has a Weighted Average Life to Maturity equal to or greater than the Weighted Average Life to Maturity of, the Indebtedness being extended, refinanced, renewed, replaced, defeased, refunded or discharged;

(c)   if the Indebtedness being extended, refinanced, renewed, replaced, defeased, refunded or discharged is subordinated in right of payment to the Obligations, such Permitted Refinancing Indebtedness has a final maturity date equal to or later than the final maturity date of, and is subordinated in right of payment to, the Obligations on terms at least as favorable to the Lenders as those contained in the documentation governing the Indebtedness being extended, refinanced, renewed, replaced, defeased, refunded or discharged; provided that no Indebtedness will be deemed to be subordinated in right of payment to any other Indebtedness solely by reason of any Liens created, or Guarantees provided, in respect of such other Indebtedness or by virtue of the fact that the holders of secured Indebtedness have entered into intercreditor agreements giving one or more of such holders priority over other such holders in the collateral held by them;

(d)   such Permitted Refinancing Indebtedness is incurred either by the Borrower or by the Restricted Subsidiary who is the obligor on the Indebtedness being extended, refinanced, renewed, replaced, defeased, refunded or discharged;

(e)   if incurred by the Borrower, such Permitted Refinancing Indebtedness may be guaranteed by the Guarantors; and

(f)   partial refinancings of the Facilities will be limited to refinancings in whole of the Revolving Credit Facility.

In addition, the Borrower shall be permitted to designate as “Permitted Refinancing Indebtedness” (by providing notice in writing of such designation to the Administrative Agents promptly upon the incurrence thereof) Indebtedness of the Borrower and its Restricted Subsidiaries otherwise meeting the requirements of clauses (a) through (f) above incurred not more than one year after the discharge (other than from the proceeds of other Indebtedness) of all or any portion of any Indebtedness outstanding under Section 7.03(b)(ii), (iii), (vi), (vii), (viii), (xi), (xii), (xiii), (xiv), (xv) or (xvii) ; provided that if such Permitted Refinancing Indebtedness is incurred more than 30 days after such discharge, the pro forma Leverage Ratio, after giving ef