Exhibit 10.3

    THE SECURITIES REPRESENTED HEREBY ARE SUBJECT TO CERTAIN RESTRICTIONS ON
                    TRANSFER AND, AMONG OTHER RESTRICTIONS,
     HAVE NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933
                      (THE "SECURITIES ACT") AND MAY NOT BE
   OFFERED, SOLD OR OTHERWISE TRANSFERRED, ASSIGNED, PLEDGED, OR HYPOTHECATED
  EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT OR AN EXEMPTION FROM
                     REGISTRATION UNDER THE SECURITIES ACT

                                 PROMISSORY NOTE


$5,250,955                                                   October 21, 2003


         FOR VALUE RECEIVED, on or before October 21, 2008, the undersigned, GP
Strategies Corporation, a Delaware corporation ("Maker"), promises to pay to
ManTech International Corporation, a Delaware corporation or its permitted
successors and assigns (the "Holder") at 12015 Lee Jackson Highway, Fairfax, VA
22033 or to such other person or address as Holder may from time to time
designate in writing, the principal sum of Five Million Two Hundred Fifty
Thousand Nine Hundred Fifty-five and No/100 Dollars ($5,250,955), or so much
thereof as shall be from time to time remain unpaid, plus interest on the
principal balance thereof from time to time outstanding from the date of this
Note until the date paid, at five percent (5%) per year payable in the manner
set forth herein. Unless otherwise defined herein, capitalized terms shall have
the meanings attributed to such terms in that certain Purchase and Sale
Agreement of even date herewith (as the same may be modified or amended from
time to time, the "Purchase Agreement") by and among the Maker and Holder.

1.       Payments.

(a)      The entire principal balance of this Note, together with all accrued
         and unpaid interest thereon and other sums payable hereunder, shall be,
         unless sooner accelerated in accordance with the terms of this Note,
         due and payable in full on October 21, 2008 (the "Maturity Date").
         Accrued interest on the unpaid principal balance hereof shall be
         payable quarterly in arrears on the 31st day of March, the 30th day of
         June, the 30th day of September, and the 31st day of December in each
         year, commencing on December 31, 2003 (each such date and the Maturity
         Date being a "Payment Date").

(b)      If any Payment Date falls on a day that is not a Business Day (as
         defined below), the payment due on such Payment Date will be made on
         the next succeeding Business Day with the same force and effect as if
         made on the Payment Date. "Business Day" means any day which is not a
         Saturday or Sunday and is not a day on which banking institutions are
         generally authorized or obligated to close in the City of New York, New
         York.

(c)      Any amounts outstanding hereunder may be prepaid, in whole or in part,
         without penalty or premium. Partial prepayments of this Note shall not



         relieve the Maker of the obligation to pay periodic installments of
         interest hereunder as and when the same would otherwise be due
         hereunder.

(d)      All payments hereunder shall be payable in lawful currency of the
         United States and in immediately available funds, and payments shall be
         applied first to any costs of collection (including, without
         limitation, reasonable attorneys' fees) incurred by Holder in enforcing
         any terms of this Note, then to accrued and unpaid interest, and then
         to reduce the principal balance hereof.

2.       Conversion.

(a)      Subject to the provisions of this Section 2, Holder may, by notice (a
         "Conversion Notice") given by Holder to the Maker from time to time as
         provided below, convert all or a portion of the principal balance of
         this Note into the common stock of Maker ("GPX Common Stock") at a
         conversion price (the "Conversion Price") equal to the closing price of
         the GPX Common Stock on the New York Stock Exchange (or, if that is not
         the principal market on which the GPX Common Stock is then traded, then
         in such principal market) on the last trading date preceding the date
         of the Conversion Notice. The number of shares of GPX Common Stock
         issuable in any such conversion shall equal the principal amount of
         this Note to be converted (the "Conversion Amount") divided by the
         applicable Conversion Price, determined to the nearest lesser whole
         number of shares.


(b)      Any Conversion Notice shall

(i)      state the Conversion Amount;

(ii)     be accompanied by the Note, for cancellation, in whole or in part, as
         provided below, and;

(iii)    include representations by Holder that;

(A)      Holder is obtaining the shares of GPX Common Stock issuable upon such
         conversion ("Conversion Shares") for investment for Holder's own
         account only and not with a view to, or for resale in connection with,
         any "distribution" thereof within the meaning of the Securities Act;

(B)      Holder understands that the Conversion Shares have not been registered
         under the Securities Act and are being issued to Holder in reliance
         upon the exemption from such registration provided by Section 4(2) of
         the Securities Act;

(C)      Holder has been informed that Conversion Shares are restricted
         securities under the Securities Act and may not be resold or
         transferred unless the Conversion Shares are first registered under the
         Federal securities laws or by any applicable state securities laws,
         unless an exemption from such registration is available; and




(D)      Holder understands that the certificate(s) evidencing the Conversion
         Shares will be imprinted with an appropriate legend which prohibits the
         transfer of the Conversion Shares unless the shares are registered or
         such registration is not required in the opinion of counsel
         satisfactory to Maker.

(c)      Notwithstanding the foregoing:

(i)      No Conversion Notice may be given (and, if given, shall not be
         effective) if the related Conversion Price would be less than $10
         (subject to appropriate adjustment for any stock split, subdivision,
         combination, recapitalization, or similar transaction).

(ii)     The aggregate Conversion Amount converted in any Conversion Period (as
         defined below) shall not exceed the sum of $1,050,191 (the "Cap
         Amount") plus the excess, if any, of the aggregate Cap Amounts of the
         prior Conversion Periods over the aggregate Conversion Amounts
         converted in the prior Conversion Periods. A "Conversion Period" shall
         mean a period commencing on any October 21 and ending on the subsequent
         October 20.

(d)      Upon each giving of a Conversion Notice in accordance with this Section
         2, Holder shall be deemed to be the holder of record of the Conversion
         Shares issuable thereupon as of the date of such Conversion Notice,
         notwithstanding that the transfer books of the Maker shall then be
         closed or certificates representing such Conversion Shares shall not
         then have been actually delivered to Holder. As soon as practicable
         after the giving of any Conversion Notice, the Maker shall deliver to
         Holder a certificate for the related Conversion Shares, together with,
         if the related Conversion Notice is for less than all of the then
         outstanding principal balance of this Note, a replacement Note with a
         principal balance equal to the prior principal balance less the
         Conversion Amount.

(e)      No later than thirty (30) days following Holder's initial conversion of
         any portion of the principal balance of this Note into GPX Common
         Stock, Maker shall prepare and file with the SEC a registration
         statement on Form S-3 or such other successor form (except that if
         Maker is not then eligible to register for resale the maximum number of
         shares of GPX Common Stock as shall be issuable upon the conversion of
         the entire outstanding principal amount of this Note on Form S-3, then
         such registration shall be on Form S-1 or any successor form) to enable
         the resale of the such shares issued or issuable from time to time.

(f)      The Maker covenants that it will at all times reserve and keep
         available out of its authorized GPX Common Stock, solely for the
         purpose of issue upon conversion of the outstanding principal amount of
         this Note, the maximum number of shares of GPX Common Stock as shall
         then be issuable upon the conversion of the entire outstanding
         principal amount of this Note.

3.       Default and Remedies.

(a)      The occurrence of any of the following events shall constitute an event
         of default (an "Event of Default"):




(i)      A default in the payment of any installment of principal or interest on
         this Note, when and as the same shall become due and payable, which
         default shall continue for five days after any applicable Payment Date.

(ii)     A failure to perform or observe any other material covenant or
         agreement contained in this Note, which failure shall continue for 30
         days after the giving of notice by Holder specifying such failure in
         reasonable detail (or, if such failure is not capable of being remedied
         within such period, for such longer period, not to exceed 60 days, as
         it is reasonably necessary to effect a remedy so long as the Maker
         continues to diligently pursue remedy of such failure).

(iii)   Theentry  of a  decree  or  order  by a court  having  jurisdiction
        adjudging  the Maker a bankrupt or  insolvent,  or  approving a petition
        seeking reorganization, arrangement, adjustment, or composition of or in
        respect of the Maker,  under federal bankruptcy law, as now or hereafter
        constituted,  or any  other  applicable  federal  or  state  bankruptcy,
        insolvency, or other similar law, and the continuance of any such decree
        or  order  unstayed  and in  effect  for a  period  of 60  days;  or the
        commencement  by the Maker of a voluntary case under federal  bankruptcy
        law, as now or hereafter constituted, or any other applicable federal or
        state  bankruptcy,  insolvency,  or other similar law, or the consent by
        the Maker to the  institution  of bankruptcy  or insolvency  proceedings
        against  it,  or the  filing  by the  Maker of a  petition  or answer or
        consent seeking reorganization or relief under federal bankruptcy law or
        any other  applicable  federal or state law, or the consent by the Maker
        to the filing of such  petition  or to the  appointment  of a  receiver,
        liquidator,  assignee, trustee, sequestrator, or similar official of the
        Maker or of any substantial  part of its property,  or the making by the
        Maker of an assignment for the benefit of creditors, or the admission by
        the Maker in writing of its inability to pay its debts generally as they
        become due, or the taking of action by the Maker in  furtherance  of any
        such action.

(b)      Upon the occurrence, and during the continuance, of an Event of
         Default, Holder may declare all or any part of the unpaid principal
         amount of this Note, and all interest accrued and unpaid thereon, to be
         immediately due and payable, without presentment, demand, notice,
         protest or other formalities of any kind, all of which are hereby
         expressly waived by the Maker. No delay or failure in exercising any
         rights under this Note in respect thereof shall operate as a waiver of
         any of the rights of any Holder.

(c)      If Holder shall institute any proceedings to enforce payment of all or
         any part of any sum due Holder hereunder, or if this Note is placed in
         the hands of an attorney for collection, or if it is collected through
         any legal proceedings, the Maker agrees to pay all costs, expenses and
         fees incurred by Holder, including reasonable attorneys' fees.

4.       Miscellaneous.

(a)      In the event any one or more of the provisions contained in this Note
         shall for any reason be held to be invalid, illegal or unenforceable in
         any respect, such invalidity, illegality or unenforceability shall not



         affect any other provision of this Note, but this Note shall be
         construed as if such invalid, illegal or unenforceable provision had
         never been contained herein or therein.

(b)      This Note may not be changed orally, but only by an agreement in
         writing signed by the party against whom any waiver, change,
         modification or discharge is sought to be enforced.

(c)      The Maker acknowledges that it has had the opportunity to obtain the
         advice of experienced counsel of its own choosing in connection with
         the negotiation and execution of this Note and to obtain the advice of
         such counsel with respect to all matters pertaining hereto, including,
         without limitation, the provision set forth herein designating the
         Commonwealth of Virginia as applicable law and the courts therein as
         appropriate venue.

(d)      This Note shall be binding upon and shall inure to the benefit of the
         Maker and its respective successors and assigns and delegates;
         provided, however, the Maker may not assign or transfer its interest
         hereunder or delegate its duties without the prior written consent of
         Holder, except to a corporation which has succeeded to substantially
         all the business and assets of the Maker or to a corporation surviving
         a merger or consolidation to which the Maker is a party and in either
         instance, such successor corporation or surviving corporation has
         assumed in writing its obligations under this Note. Notwithstanding
         anything stated herein to the contrary, but subject to Section 4(g) of
         the Purchase Agreement, the Maker agrees that all of Holder's right,
         title and interest in and to this Note has been, or will be,
         collaterally assigned to its current and future lenders (currently
         Citizen's Bank of Pennsylvania, acting in its capacity as the
         administrative agent for the lender parties) which are parties to that
         certain Business Loan and Security Agreement dated December 17, 2001
         (as the same has been and may be amended, modified substituted or
         replaced from time to time) and the Maker will continue be bound by all
         the terms and provisions of this Note as it may relate to (or be
         enforced by) Holder's lenders as successors and assigns hereunder.
         Except as provided herein, prior to April 21, 2006, Holder may not
         assign or transfer this Note without the prior written consent of
         Maker. Any assignee or transferee of this Note shall agree to be bound
         by the provisions of Section 4(g) of the Purchase Agreement.

(e)      This Note shall be governed by and construed in accordance with the
         laws of the Commonwealth of Virginia, excluding any conflicts or choice
         of law rule or principle that might otherwise refer construction or
         interpretation of this Note to the substantive law of another
         jurisdiction. The Maker hereby submits to the nonexclusive jurisdiction
         of the United States District Court for the Eastern District of
         Virginia and of any Virginia state court for purposes of all legal
         proceedings arising out of or relating to this Note or the transactions
         contemplated hereby. The Maker irrevocably waives, to the fullest
         extent permitted by law, any objection which it may now or hereafter
         have to the laying of the venue of any such proceeding brought in such
         a court, any claim that any such proceeding brought in such a court has
         been brought in an inconvenient forum, and any right to which it may be
         entitled on account of its place of residence or domicile.

(f)      The Maker irrevocably designates and appoints CT Corporation System,
         whose address is 4701 Cox Road, Suite 301, Glenn Allen, VA 23060-6802,
         as its agent to receive on its behalf' service of all process in any



         such proceeding in any court in the Commonwealth of Virginia, such
         service being hereby acknowledged by the Maker to be effective and
         binding on it in every respect. A copy of any such process so served
         shall be mailed by registered or certified mail to the Maker at the
         address to which notices are to be addressed in accordance with the
         Purchase Agreement, except that any failure to mail such copy shall not
         affect the validity of service of process. The Maker shall at all times
         maintain an agent for service of process pursuant to this provision. If
         the Maker fails to appoint such an agent, or if such agent refuses to
         accept service, the Maker hereby agrees that service upon it by mail to
         the address to which notices are to be addressed in accordance with the
         Purchase Agreement shall constitute sufficient notice. Nothing herein
         shall affect the right to serve process in any other manner permitted
         by law or shall limit the right of Holder to bring proceedings against
         the Maker in the courts of any other jurisdiction.

(g)      Time is of the essence. No failure or delay by Holder to insist upon
         the strict performance of any term, condition, covenant or agreement
         set forth in this Note, or to exercise any right, power or remedy
         consequent upon a breach thereof, shall constitute a waiver of such
         term, condition, covenant or agreement or of any such breach, or
         preclude Holder from exercising any such right, power or remedy at any
         later time or times.


                                      MAKER:

                                      GP Strategies Corporation

ATTEST:


By:    /s/ Andrea D. Kantor           By:      /s/ Scott N. Greenberg
Name:  Andrea D. Kantor               Name:    Scott N. Greenberg
Title: Vice President and             Title:   President and Chief
       General Counsel                         Financial Officer