PROXY/VOTING INSTRUCTION



                           MORGAN STANLEY GROUP INC.
 THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS OF MORGAN STANLEY
             FOR THE SPECIAL MEETING OF STOCKHOLDERS, MAY 28, 1997

     The undersigned hereby appoints Jonathan M. Clark and Philip N. Duff and
each of them, attorneys and proxies with full power of substitution, to
represent and to vote on behalf of the undersigned all of the shares of common
stock of Morgan Stanley Group Inc. ("Morgan Stanley") which the undersigned is
entitled in any capacity to vote if personally present at the Special Meeting of
Stockholders of Morgan Stanley to be held at 1585 Broadway, New York, New York,
on Wednesday, May 28, 1997 at 9:30 A.M., local time, and at any and all
adjournments or postponements thereof, upon the following proposal more fully
described in the Notice of Special Meeting of Stockholders dated April 11, 1997
and the Dean Witter, Discover & Co. ("Dean Witter Discover") and the Morgan
Stanley Joint Proxy Statement/Prospectus dated April 11, 1997 and, in their
discretion, upon all matters incident to the conduct of the Special Meeting and
all matters presented at the Special Meeting but which were not known to the
Morgan Stanley Board of Directors a reasonable time before the solicitation of
this proxy.

     With respect to the shares of common stock of Morgan Stanley, if any,
allocated to my account pursuant to the Morgan Stanley Group Inc. 1988 Equity
Incentive Compensation Plan, as amended, and 1995 Equity Incentive Compensation
Plan (the "EICP Stock") not subject to any voting agreement, the undersigned
hereby directs State Street Bank and Trust Company, as trustee (the "Trustee")
under the Trust Agreement dated as of April 1, 1994 and amended as of April 3,
1996, (a) to vote such shares of EICP Stock at the Special Meeting and at any
and all adjournments or postponements thereof in accordance with the directions
set forth on the reverse side and (b) to grant a proxy to Jonathan M. Clark and
Philip N. Duff, and each of them, giving them discretion to vote such shares of
EICP Stock in connection with such other business as may come before the Special
Meeting. I understand that the Trustee will not vote any allocated shares of
EICP Stock for which no instruction is received.

     With respect to the shares of preferred stock ("ESOP Stock") of Morgan
Stanley allocated to my stock account pursuant to the Morgan Stanley Group Inc.
and Subsidiaries Employee Stock Ownership Plan (the "ESOP Plan") and a
proportion of shares of ESOP Stock held in the trust which has not been
allocated to participants in the ESOP Plan, if any, the undersigned hereby
directs Northern Trust Company, as trustee (the "ESOP Trustee"), (a) to vote
such allocated shares of ESOP Stock at the Special Meeting and at any and all
adjournments or postponements thereof in accordance with the directions set
forth on the reverse side, (b) to vote such unallocated shares of ESOP Stock in
accordance with the provisions of the ESOP Plan and (c) to grant a proxy to
Jonathan M. Clark and Philip N. Duff, and each of them, giving them discretion
to vote such shares of ESOP Stock in connection with such other business as may
come before the Special Meeting. I understand that the ESOP Trustee will not
vote any allocated shares of ESOP Stock for which no instruction is received.

THIS PROXY REVOKES ALL PRIOR PROXIES GIVEN BY THE UNDERSIGNED AND, WHEN PROPERLY
EXECUTED, WILL BE VOTED IN THE MANNER DIRECTED HEREIN BY THE UNDERSIGNED
STOCKHOLDER. IF NO DIRECTION IS GIVEN, THIS PROXY, WHEN PROPERLY EXECUTED, WILL
BE VOTED FOR PROPOSAL 1 AND IN THE DISCRETION OF THE PROXIES ON ALL OTHER
MATTERS THAT MAY PROPERLY COME BEFORE THE SPECIAL MEETING. THE UNDERSIGNED
HEREBY ACKNOWLEDGES RECEIPT OF THE NOTICE OF SPECIAL MEETING OF STOCKHOLDERS AND
THE JOINT PROXY STATEMENT/PROSPECTUS (WITH ALL ENCLOSURES AND ATTACHMENTS) DATED
APRIL 11, 1997 RELATED TO THE SPECIAL MEETING.

     IMPORTANT - This Proxy must be signed and dated on the reverse side.
                          (Continued on reverse side)
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[X] Please mark your            When OK to Print--Remove ALL Red Items    0306
    votes as in this
    example

THE MORGAN STANLEY BOARD OF DIRECTORS PROPOSES AND RECOMMENDS A VOTE FOR THE 
FOLLOWING PROPOSAL:

                                                  FOR      AGAINST     ABSTAIN
1. Proposal to approve and adopt the Amended      [ ]        [ ]         [ ]
   and Restated Agreement and Plan of
   Merger, dated as of April 10, 1997
   between Morgan Stanley and Dean Witter
   Discover, providing for the merger of
   Morgan Stanley with and into Dean
   Witter Discover.

 NO TEXT PRINT IN THIS ADDRESS AREA

Dated__________________________________________________________________, 1997

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Signature of Stockholder(s)--please sign name exactly as imprinted (do not
print). Please indicate any changes in address.

NOTE: Executors, administrators, trustees and others signing in a representative
capacity should indicate the capacity in which they sign. An authorized officer 
may sign on behalf of a corporation and should indicate the name of the 
corporation and his or her capacity. If shares are held jointly, EACH holder 
should sign.


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                             FOLD AND DETACH HERE