QuickLinks -- Click here to rapidly navigate through this document

Exhibit 10.90

AMENDED AND RESTATED
EMPLOYMENT RETENTION AGREEMENT
FOR MIRANT SERVICES LLC

        This Amended and Restated Employment Retention Agreement ("Agreement")
is made and entered into by and between Mirant Services LLC (the "Company") and
John Ragan (the "Employee") on                        , 2002, to be effective as
of March 1, 2002

W I T N E S S E T H:

        WHEREAS, the Employee is an employee of the Company or another Mirant
Subsidiary; and

        WHEREAS, the Company wishes to continue to encourage the Employee to
remain with the Company; and

        WHEREAS, Company desires to provide Employee with additional
compensation for services Employee has or will provide for the Company;

        NOW, THEREFORE, in consideration of the premises, and the agreements of
the parties set forth in this Agreement, and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereby agree as follows:

        1.     Definitions.    For purposes of this Agreement, the following
terms shall have the following meanings:

        (a)   "Award Amount" shall mean the retention award payments payable to
the Employee under Section 2 of this Agreement.

        (b)   "Change in Control" shall have the meaning of such term as set
forth in the Change in Control Benefit Plan Determination Policy.

        (c)   "Change in Control Benefit Plan Determination Policy" shall mean
the Mirant Corporation Change in Control Benefit Plan Determination Policy, as
approved by the Board of Directors of Mirant, as such policy may be amended from
time to time in accordance with the provisions therein.

        (d)   "Company" shall mean Mirant Services LLC, its successors and
assigns.

        (e)   "Effective Date" shall mean the date of execution of this
Agreement, unless otherwise provided herein.

        (f)    "Mirant" shall mean Mirant Corporation, a Delaware corporation,
its successors and assigns.

        (g)   "Termination for Cause" or "Cause" shall have the meaning of such
term as set forth in the Change in Control Benefit Plan Determination Policy.

        2.     Payment of Award Amounts.    Employee will receive the Award
Amounts as follows:

$245,000 on the earliest of (i) September 30, 2004, (ii) the occurrence of a
Change in Control, or (iii) the termination of Employee's employment with the
Company or another Mirant Subsidiary due to the Employee's death, Disability or
termination by the employer without Cause.; and

$245,000 on the earliest of (i) September 30, 2005, (ii) the occurrence of a
Change in Control, or (iii) the termination of Employee's employment with the
Company or another Mirant Subsidiary due to the Employee's death, Disability or
termination by the employer without Cause

--------------------------------------------------------------------------------

To receive these Award Amounts, Employee must (i) have remained as a Company or
Mirant Employee up to the Award Amount payment date(s); and (ii) must be
performing in a satisfactory manner at that time (as determined by Employee's
most recent performance evaluation).

        3.     Termination for Cause or Employee Resignation.    In the event of
(i) the Employee's Termination for Cause; (ii) the Employee's resignation for
any reason, or (iii) the Employee's retirement, prior to the payment dates as
set forth in Section 2, the Employee shall forfeit any Award Amount the Company
has not yet paid, and the Company will have no further obligations with respect
to any unpaid amount under this Agreement.

        4.     Confidentiality and Legal Process.    The Employee represents and
agrees that he will keep the terms, amount and fact of this Agreement
confidential and that he will not hereafter disclose any information concerning
this Agreement to anyone other than his personal agents, including, but not
limited to, any past, present, or prospective employee or applicant for
employment with the Company or any Mirant Subsidiary. Notwithstanding the
foregoing, nothing in this Agreement is intended to prohibit the Employee from
performing any duty or obligation that shall arise as a matter of law.
Specifically, the Employee shall continue to be under a duty to respond
truthfully to matters of law and shall continue to be under a duty to respond
truthfully to any legal and valid subpoena or other legal process. This
Agreement is not intended in any way to proscribe the Employee's right and
ability to provide information to any federal, state or local government in the
lawful exercise of such government's governmental functions. If Employee
breaches the restrictive covenants as set forth in this Section 4, then Company
reserves the right to render this Agreement null and void and opt not to make
any or future Award Amount payments to Employee as stipulated by this Agreement.

        5.     Assignability.    Neither the Employee, his estate, his
beneficiaries, nor his legal representative shall have any rights to commute,
sell, assign, transfer or otherwise convey the right to receive any payments
under this Agreement, which payments and the rights thereto are expressly
declared to be nonassignable and nontransferable. Any attempt to assign or
transfer the right to payments of this Agreement shall be void and have no
effect.

        6.     Unsecured General Creditor.    Unless the Company shall in its
discretion determine otherwise, the benefits payable to the Employee under this
Agreement shall not be funded in any manner and shall be paid by the Company out
of its general assets, which assets are subject to the claims of the Company's
creditors.

        7.     Mirant Guarantee.    If the Company fails or refuses to make
payments under this Agreement, the Employee may have the right to obtain payment
by Mirant under the terms of the "Guarantee Agreement Concerning Mirant Services
LLC Compensation and Benefit Arrangements" entered into by the Company and
Mirant. The Employee's right to payment is not increased as a result of this
Guarantee. The Employee has the same right to payment from Mirant as from the
Company. Any demand to enforce this Guarantee should be made in writing and
should reasonably and briefly specify the manner and the amount the Company has
failed to pay.

        8.     Amendment; Modification; Termination.    Except as otherwise
provided herein, this Agreement may be emended, modified, or terminated only by
a writing executed by the parties hereto.

        9.     No Effect On Other Arrangements.    It is expressly understood
and agreed that the payments made in accordance with this Agreement are in
addition to any other benefits or compensation to which the Employee may be
entitled or for which he may be eligible, whether funded or unfunded, by reason
of his employment with the Company.

        10.   Tax Withholding.    There shall be deducted from each payment
under this Agreement the amount of any tax required by any governmental
authority to be withheld and paid over by the Company to such governmental
authority for the account of the Employee.

        11.   Compensation.    Any compensation contributed on behalf of the
Employee under this Agreement shall not be considered "compensation", as the
term is defined in the Mirant Services LLC Employee Savings Plan, or the Mirant
Services LLC Pension Plan. Payment of the Award Amount to

--------------------------------------------------------------------------------

the Employee shall not be considered wages, salaries or compensation under any
other employee benefit plan.

        12.   No Guarantee of Employment.    No provision of this Agreement
shall be construed to affect in any manner the existing rights of the Company to
suspend, terminate, alter, or modify, whether or not for Cause, the employment
relationship of the Employee and the Company.

        13.   Transfer of Employment to Mirant or another Mirant
Subsidiary.    In the event that the Employee's employment by the Company is
terminated prior to the scheduled payment date of the Award Amount, and the
Employee becomes immediately re-employed by Mirant or another Mirant Subsidiary,
the Company shall assign this Agreement to Mirant or such Mirant Subsidiary;
Mirant or such Mirant Subsidiary shall accept such assignment or cause such
Mirant Subsidiary to accept such assignment; such assignee shall become the
"Company" for all purposes under this Agreement; and this Agreement shall be
amended to appropriately reflect the performance of such assignee. In the event
of such assignment, the expense of this Agreement shall be the Company's sole
responsibility.

        14.   Governing Law.    This Agreement, and all its rights under it,
shall be governed by and construed in accordance with the laws of the State of
Georgia.

        IN WITNESS WHEREOF, this Agreement has been executed by the parties
first listed above on the date first listed above, to be effective as of the
Effective Date.

 
 
MIRANT SERVICES LLC
 
 
By:
 
/s/  VANCE BOOKER      

--------------------------------------------------------------------------------

 
 
EMPLOYEE:
 
 
/s/  JOHN W. RAGAN      

--------------------------------------------------------------------------------

Attest:
 
 
By:
 
 
 
     

--------------------------------------------------------------------------------

   

--------------------------------------------------------------------------------

QuickLinks

AMENDED AND RESTATED EMPLOYMENT RETENTION AGREEMENT FOR MIRANT SERVICES LLC