EXHIBIT NO. EX-99.d.6


                        DIMENSIONAL INVESTMENT GROUP INC.

                             GLOBAL 25/75 PORTFOLIO

                          INVESTMENT ADVISORY AGREEMENT

     AGREEMENT  made  this  ___  day  of  ____________,  2003,  by  and  between
DIMENSIONAL  INVESTMENT  GROUP INC.,  a Maryland  corporation  (the  "Fund") and
DIMENSIONAL FUND ADVISORS INC., a Delaware corporation (the "Advisor").

     1.  Duties of Advisor.  The Fund  hereby  employs the Advisor to manage the
investment and reinvestment of the assets of:

                             Global 25/75 Portfolio

(the  "Portfolio"),   to  continuously  review,  supervise  and  administer  the
Portfolio's investment program, to determine in its discretion the securities to
be purchased or sold and the portion of the Portfolio's assets to be uninvested,
to provide the Fund with records  concerning the Advisor's  activities which the
Fund is  required  to  maintain,  and to render  regular  reports  to the Fund's
officers  and the Board of  Directors of the Fund,  all in  compliance  with the
objectives, policies and limitations set forth in the Portfolio's prospectus and
applicable laws and regulations.  The Advisor accepts such employment and agrees
to provide, at its own expense, the office space,  furnishings and equipment and
the  personnel  required by it to perform the services  described  herein on the
terms and for the compensation provided herein.

     2. Portfolio Transactions.  The Advisor is authorized to select the brokers
or dealers that will execute the purchases and sales of portfolio securities for
the  Portfolio  and is  directed  to use its  best  effort  to  obtain  the best
available prices and most favorable executions,  except as prescribed herein. It
is understood that the Advisor will not be deemed to have acted  unlawfully,  or
to have  breached a  fiduciary  duty to the Fund or to the  Portfolio,  or be in
breach  of any  obligation  owing to the  Fund or to the  Portfolio  under  this
Agreement, or otherwise,  solely by reason of its having caused the Portfolio to
pay a member of a securities  exchange,  a broker or a dealer a  commission  for
effecting a securities  transaction for the Portfolio in excess of the amount of
commission another member of an exchange, broker or dealer would have charged if
the Advisor  determines in good faith that the commission paid was reasonable in
relation to the brokerage or research services  provided by such member,  broker
or  dealer,  viewed in terms of that  particular  transaction  or the  Advisor's
overall responsibilities with respect to its accounts, including the Fund, as to
which it exercises investment discretion.  The Advisor will promptly communicate
to the  officers  and  directors  of  the  Fund  such  information  relating  to
transactions for the Portfolio as they may reasonably request.

     3.  Compensation  of the  Advisor.  For the  services to be rendered by the
Advisor as provided in Section 1 of this Agreement, the Advisor shall receive no
compensation.

     4.  Other  Services.  At the  request  of the  Fund,  the  Advisor,  in its
discretion,  may  make  available  to the  Fund  office  facilities,  equipment,
personnel and other services. Such office facilities,  equipment,  personnel and
services shall be provided for or rendered by the Advisor and billed to the Fund
at the  Advisor's  cost  and,  where  applicable,  the  cost  thereof  shall  be
apportioned  among the several  portfolios  of the Fund  proportionate  to their
respective utilization thereof.

     5.  Reports.  The  Fund and the  Advisor  agree to  furnish  to each  other
information  with  regard to their  respective  affairs  as each may  reasonably
request.

     6. Status of the  Advisor.  The services of the Advisor to the Fund or with
respect to the Portfolio are not to be deemed  exclusive,  and the Advisor shall
be free to render similar services to others as long as its services to the Fund
or to the Portfolio are not impaired thereby.  The Advisor shall be deemed to be
an independent  contractor and shall,  unless  otherwise  expressly  provided or
authorized,  have no authority  to act for or  represent  the Fund in any way or
otherwise be deemed an agent of the Fund.

     7. Liability of Advisor.  No provision of this Agreement shall be deemed to
protect the Advisor against any liability to the Fund or the shareholders of the
Portfolio to which the Advisor  might  otherwise be subject by reason of willful
misfeasance,  bad faith or gross  negligence in the performance of its duties or
the reckless disregard of its obligations under this Agreement.

     8. Permissible Interests. Subject to and in accordance with the charters of
the Fund and the Advisor, respectively, directors, officers, and shareholders of
the Fund are or may be interested  in the Advisor (or any successor  thereof) as
directors, officers or shareholders, or otherwise;  directors,  officers, agents
and  shareholders  of  the  Advisor  are or may be  interested  in the  Fund  as
directors,  officers,  shareholders  or  otherwise;  and  the  Advisor  (or  any
successor) is or may be interested in the Fund as a shareholder or otherwise and
the effect of any such interrelationships shall be governed by said charters and
the  provisions  of the  Investment  Company Act of 1940,  as amended (the "1940
Act").

     9.  Duration and  Termination.  This  Agreement  shall become  effective on
_________,   2003  and  shall  continue  in  effect  until  _______,  2005,  and
thereafter,  only if such continuance is approved at least annually by a vote of
the Fund's Board of Directors, including the vote of a majority of the directors
who are not parties to this  Agreement or interested  persons of any such party,
cast in person,  at a meeting called for the purpose of voting on such approval.
In addition,  the question of  continuance of this Agreement may be presented to
the shareholders of the Fund; in such event,  such continuance shall be effected
only if  approved  by the  affirmative  vote of the holders of a majority of the
respective outstanding voting securities of the Portfolio.

     This Agreement may at any time be terminated without payment of any penalty
either by vote of the Board of  Directors  of the Fund or by vote of the holders
of a majority of the respective  outstanding voting securities of the Portfolio,
on sixty days written notice to the Advisor.

     This  Agreement  shall   automatically   terminate  in  the  event  of  its
assignment.

     This  Agreement  may be terminated by the Advisor after ninety days written
notice to the Fund.

     Any notice under this  Agreement  shall be given in writing,  addressed and
delivered, or mailed postpaid, to the other party at any office of such party.

     As used in this section, the terms "assignment,"  "interested persons," and
a "vote of the holders of majority of the outstanding securities" shall have the
respective  meanings set forth in Section  2(a)(4),  Section  2(a)(19),  Section
2(a)(42) of the 1940 Act and Rule 18f-2 thereunder.

     10. Severability.  If any provision of this Agreement shall be held or made
invalid by a court decision,  statute, rule or otherwise,  the remainder of this
Agreement shall not be affected thereby.

     IN WITNESS  WHEREOF,  the parties  hereby have caused this  Agreement to be
executed this ___ day of ____________, 2003.



DIMENSIONAL FUND                           DIMENSIONAL INVESTMENT
ADVISORS INC.                              GROUP INC.


By:    ____________________                By:  _____________________
       Catherine L. Newell                      Michael T. Scardina
       Vice President and Secretary             Vice President, Chief
                                                Financial Officer and Treasurer