EXHIBIT 10.1 Siebel Systems, Inc. Nonqualified Deferred Compensation Plan

Exhibit 10.1

Siebel Systems, Inc.
Nonqualified Deferred Compensation Plan

Effective September 1, 2004

1.     Purpose and Definitions. Siebel Systems, Inc. hereby adopts this Siebel Systems, Inc. Nonqualified Deferred Compensation Plan. The Plan was established for the purpose of providing the Company's eligible employees with a program for deferring compensation that otherwise would be earned during employment.

It is intended that the Plan and its related Trust shall constitute an unfunded deferred compensation arrangement for the benefit of a select group of management or highly compensated employees of the Company and its subsidiaries for purposes of the federal income tax laws and ERISA, and all documents, agreements or instruments made or given pursuant to the Plan shall be interpreted so as to effect such intent.

Capitalized terms used in this Plan shall be defined as follows:

A.    "401(k) Plan" means the Siebel Systems, Inc. 401(k) Salary Deferral Plan, as it may be amended from time to time.

B.    "Account" means the bookkeeping Account established on behalf of a Participant into which Deferred Compensation and Company Contributions, plus earnings and losses thereon, are recorded.

C.    "Base Pay" means a Participant's basic salary without regard to bonuses, commissions and other incentive compensation.

D.   "Board of Directors" means the Board of Directors of Siebel Systems, Inc.

E.    "Change in Control Election" means the Participant election with respect to a Change in Control permitted under Section 7.

F.     "Change in Control" means any event described in Section 7.

G.   "Code" means the Internal Revenue Code of 1986, as amended from time to time.

H.   "Company Contributions" means contributions to the Plan made by the Company, if any, pursuant to Section 3.E.

I.       "Company" means Siebel Systems, Inc. and its affiliates.

J.      "Compensation Committee" means the Compensation Committee of the Board of Directors of the Company.

K.   "Deduction Limitation" means the limitations on payment of an Account described in Section 6.F.

L.    "Deferred Compensation" means the amount of Total Compensation or Base Pay, as applicable, that a Participant elects to defer into the Plan.

M.  "Disability" means that the Participant has a mental or physical disability as determined by the Plan Committee in accordance with the standards and procedures used for determining Disability under the Company's broad-based regular long-term disability plan, if any, under which the Participant is a participant. At any time that the Company does not maintain such a long-term disability plan, "Disabled" or "Disability" shall mean the inability of a Participant, as determined by the Plan Committee, substantially to perform such Participant's regular duties and responsibilities due to a medically determinable physical or mental illness which has lasted, or can reasonably be expected to last, for a period of six (6) consecutive months, but only to the extent that such definition does not violate the Americans with Disabilities Act.

N.   "Election Form" means the form provided by the Plan Committee on which a Participant may elect to defer his or her Total Compensation or Base Pay for a Plan Year and elect the time and form of distributions from the Plan.

O.   "ERISA" means the Employee Retirement Income Security Act of 1974, as amended from time to time.

P.    "Fixed Date Payout" means the in-service withdrawal permitted under Section 6.B.

Q.   "Investment Funds" means the investment funds described under Section 5.A.

R.    "New Employee" means an employee who first performs services for the Company after the first day of a Plan Year, or for the first Plan Year, who first performs services for the Company on or after January 1, 2003 and on or before August 31, 2004.

S.     "Normal Retirement Age" means the date on which the Participant attains fifty-nine and one-half (59 ½) years of age.

T.    "Participant" means each common-law employee on the United States payroll of the Company who is designated by the Compensation Committee, in accordance with the Plan terms, as an eligible employee who may elect to participate in the Plan.

U.   "Plan Committee" means the Plan Administrative Committee established under Section 10.

V.    "Plan" means this Siebel Systems, Inc. Nonqualified Deferred Compensation Plan, as it may be amended from time to time.

W. "Plan Year" means the calendar year. The first Plan Year shall be the short period from September 1, 2004 to December 31, 2004.

X.   "Termination of Employment" means the termination of the Participant's employment with the Company for any reason other than retirement at or following attainment of Normal Retirement Age.

Y.   "Total Compensation" means a Participant's compensation for purposes of the 401(k) Plan, but without limitation under Section 401(a)(17) of the Code, including Base Pay and Variable Pay, but excluding stock option earnings.

Z.    "Trust" means the Siebel Systems, Inc. Nonqualified Deferred Compensation Trust established in conjunction with this Plan.

AA.                      "Variable Pay" means a Participant's commissions and bonuses and any other incentive compensation.

2.     Eligibility. Each common-law employee of the Company and its principal subsidiaries who is on the United States payroll and who is designated by the Compensation Committee as an eligible employee may participate in the Plan for a Plan Year.

Unless otherwise determined by the Compensation Committee, the following classes of employees may elect to be Participants in the Plan. An election to participate in the Plan shall be made by completing and filing the Election Form described in Section 3.A.

A.    Except as specified in Section 2.B below, employees on the United States payroll of the Company whose Total Compensation in the immediately preceding calendar year (the "look back year") was equal to or in excess of One Hundred Seventy-Five Thousand Dollars ($175,000);

B.    With respect to New Employees, (i) for the year of hire, an employee whose Base Pay on an annualized basis is at least One Hundred Fifty Thousand Dollars ($150,000) in his or her year of hire and (ii) for the year following the year of hire, an employee whose Base Pay on an annualized basis in the look back year was at least One Hundred Fifty Thousand Dollars ($150,000).

3.     Election to Defer Compensation. A Participant may elect to defer receipt of a specified percentage, from one percent (1%) to eighty percent (80%), of the Participant's Base Pay and/or from one percent (1%) to one hundred percent (100%) of the Participant's Variable Pay. In determining the amount of Base Pay eligible for deferral under this Plan, an amount of Base Pay must remain undeferred such that the Participant's contributions under the 401(k) Plan, other premiums and contributions for benefits elected by the Participant and/or required by the Company, as well as withholdings from pay for benefits, repayments to the Company previously agreed to by the Participant, and taxes may be made. In determining the amount of Variable Pay eligible for deferral under this Plan, an amount of Variable Pay must remain undeferred such that any draws, or other repayments to the Company previously agreed to by the Participant, may be made. The Company may adjust a Participant's deferral election in order to cause the election to meet the requirements of this paragraph.

A.    Election Form. Each Participant may elect to defer receipt of his or her Total Compensation or Base Pay, as applicable, by filing with the Company:

                                                        i.            For the first Plan Year, the Election Form provided by the Plan Committee at any time on or before August 31, 2004, for Total Compensation to be paid for services rendered after August 31, 2004;

                                                      ii.            For subsequent Plan Years, the Election Form provided by the Plan Committee at any time prior to December 31 preceding the first day of the relevant Plan Year with respect to Total Compensation to be earned in such subsequent Plan Year;

                                                    iii.            For New Employees, the Election Form provided by the Plan Committee within thirty (30) days following the date the New Employee is notified in writing by the Compensation Committee, or its designee, that the New Employee is eligible to participate in the Plan for Base Pay earned after the date the Election Form is filed with the Company.

The Election Forms shall specify the form in which payments from the Plan shall be paid to the Participant and, subject to the limitations of Section 6, the time at which such payments shall commence. The elections shall be delivered to the Plan Committee, or its designee, in such form as may be permitted by the Plan Committee, including electronic or telephonic communication.

B.    Effect of No Election to Defer. If a Participant makes no election to defer Total Compensation or Base Pay under the Plan for a Plan Year, any Total Compensation or Base Pay that the Participant is entitled to receive for the Plan Year shall be paid to the Participant at such time, in such manner and in such amounts as is consistent with the normal payroll practices of the Company or as provided in the relevant incentive compensation plan or commission program.

C.    Leave of Absence. If a Participant is authorized by the Company for any reason to take a paid leave of absence from the employment of the Company, the Participant shall continue to be considered employed by the Company and the Deferred Compensation shall continue to be withheld during such paid leave of absence in accordance with this Section 3. For purposes of clarity, payment of short-term, long-term or state sponsored disability payments to Participant do not constitute a "paid leave of absence" for purposes of this Plan; however, any Company paid maternity benefit will constitute a "paid leave of absence" for purposes of this Plan.

If a Participant is authorized by the Company for any reason to take an unpaid leave of absence from the employment of the Company, or if a Participant is on leave of absence as a result of his or her Disability, the Participant shall continue to be considered employed by the Company and the Participant shall be excused from making deferrals from the date the unpaid leave of absence begins until the earlier of the date the leave of absence expires or the Participant returns to a paid employment status. Upon such expiration or return, as the case may be, deferrals shall resume for the remaining portion of the Plan Year in which the expiration or return occurs, based on the deferral election, if any, previously made by the Participant for that Plan Year.

D.   Irrevocable Election to Defer. Following a Participant's filing of an Election Form with the Company pursuant to Section 3.A above, such election to defer compensation shall be irrevocable with respect to the Plan Year to which it relates, and the Participant shall not be permitted to change such deferral election for the remainder of the Plan Year for which the deferral election is in effect, except as otherwise set forth herein. Notwithstanding the foregoing, the election may be terminated with respect to Total Compensation or Base Pay not yet earned by mutual agreement in writing between the Participant and the Plan Committee. Such termination, if approved, shall be effective beginning with Total Compensation or Base Pay to be earned during the period following the execution of such mutual agreement.

E.    Company Contribution. The Company, in its sole discretion, may make such contributions to the Accounts of Participants as the Company may determine. If the Company elects to make Company Contributions for a Plan Year, such Company Contributions shall be in the amount determined by the Company for the relevant Plan Year and shall be allocated to the Accounts of such Participants as shall be determined by the Company. Nothing in this Section 3.E requires the Company to make Company Contributions for any Plan Year, nor, if Company Contributions are made, to allocate such Company Contributions in an equal or proportional manner among Participant Accounts. If Company Contributions are made by the Company, such contributions shall be bookkeeping entries and shall not be subject to investment direction by the Participant. The Company also reserves the right to impose a vesting schedule on any Company Contribution made for any Plan Year. Company Contributions, if made, shall be subject to the same terms, conditions and restrictions as apply to Deferred Compensation under this Plan.

4.     Crediting of Deferred Compensation and Any Company Contributions. All amounts of a Participant's Deferred Compensation pursuant to Section 3 and Company Contributions, if any, made to the Plan on behalf of a Participant shall be credited to such Participant's Account and may be contributed to the Trust. Such Accounts shall be bookkeeping entries only and shall be credited with earnings and losses in accordance with Section 5. Except as otherwise provided in Section 6, the amount to be paid to a Participant from the Plan in accordance with Section 6 shall be an amount equal to the balance of the Participant's Account at the time of payment.

5.     Investment of Deferred Compensation and Company Contributions.

A.    Investment Funds. The Investment Funds referred to in this Section 5 shall be selected by the Plan Committee and may (but need not) be the same Investment Funds in which investments under the 401(k) Plan are invested. Any amounts held under this Plan shall be segregated from the amounts held under the 401(k) Plan and shall be administered in accordance with the terms and conditions of this Plan and shall not be administered under the terms and conditions of the 401(k) Plan.

B.    Deemed Investments. In accordance with and subject to the rules and procedures that are established from time to time by the Plan Committee, in its sole discretion, amounts shall be credited or debited to a Participant's Account in accordance with the following rules:

                                                        i.            A Participant, in connection with his or her deferral election shall elect, on the Election Form, one or more Investment Funds to be used to determine the additional amounts to be credited (or charged, as the case may be) to his or her Account. The Participant also may, from time to time, by submitting an Election Form to the Plan Committee, or its designee, change the portion of his or her Account allocated to each Investment Fund. If an investment election is made in accordance with the previous sentence, it shall become effective as soon as administratively practicable and shall continue thereafter until changed in accordance with the previous sentence. Changes may be made to investment elections at any time during the Plan Year. Any investment election from a Participant under this Section 5 shall be delivered to the Plan Committee, or its designee, in such form as permitted by the Plan Committee, including electronic or telephonic communication.

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