(HATTERAS LOGO)

                                    EXHIBIT A

           COVER LETTER TO OFFER TO PURCHASE AND LETTER OF TRANSMITTAL

   IF YOU DO NOT WANT TO SELL YOUR LIMITED PARTNERSHIP INTERESTS AT THIS TIME,
     PLEASE DISREGARD THIS NOTICE. THIS IS SOLELY NOTIFICATION OF THE FUND'S
                                  TENDER OFFER.

September 29, 2008

Dear Hatteras Multi-Strategy Institutional Fund, L.P. Partner:

     We are writing to inform you of important dates relating to a tender offer
by Hatteras Multi-Strategy Institutional Fund, L.P. (the "Fund"). IF YOU ARE NOT
INTERESTED IN HAVING THE FUND REPURCHASE YOUR LIMITED PARTNERSHIP INTEREST OR A
PORTION OF YOUR INTEREST IN THE FUND ("INTEREST") VALUED AS OF DECEMBER 31,
2008, PLEASE DISREGARD THIS NOTICE AND TAKE NO ACTION.

     The tender offer period will begin on September 29, 2008 and will end at
12:00 midnight, Eastern Standard Time, on OCTOBER 27, 2008, AT WHICH POINT THE
TENDER OFFER WILL EXPIRE. The purpose of the tender offer is to provide
liquidity to Partners of the Fund that hold Interests. Interests may be
presented to the Fund for purchase only by tendering them during one of the
Fund's announced tender offers.

     Should you wish to tender your Interest or a portion of your Interest for
purchase by the Fund during this tender offer period, please complete and return
the enclosed Letter of Transmittal so that it is received by UMB Fund Services,
Inc. ("UMBFS") no later than OCTOBER 27, 2008. If you do not wish to have all or
any portion of your Interest repurchased, simply disregard this notice. NO
ACTION IS REQUIRED IF YOU DO NOT WISH TO HAVE ANY PORTION OF YOUR INTEREST
REPURCHASED.

     If you would like to tender your Interest, you should complete, sign and
either (i) mail (via certified mail, return receipt requested) or otherwise
deliver the Letter of Transmittal to Hatteras Multi-Strategy Institutional Fund,
L.P., c/o UMB Fund Services, Inc. at P.O. Box 1623, Milwaukee, Wisconsin
53201-1623, Attention: Tender Offer Administrator; or (ii) fax it to UMBFS at
(816) 860-3138, Attention: Tender Offer Administrator (if by fax, please deliver
an original, executed copy promptly thereafter), so that it is RECEIVED BEFORE
12:00 MIDNIGHT, EASTERN STANDARD TIME, ON OCTOBER 27, 2008.

     If you have any questions, please refer to the enclosed Offer to Purchase
document, which contains additional important information about the tender
offer, or call the Tender Offer Administrator at UMBFS at (800) 504-9070.

Sincerely,

Hatteras Multi-Strategy Institutional Fund, L.P.