CERTIFICATION PURSUANT TO RULE 30A-2(B) UNDER THE 1940 ACT AND SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Richard Sipes, Principal Executive Officer of UBS Multi-Strat Fund, L.L.C. (the "Registrant"), certify that: 1. The Form N-CSR of the Registrant (the "Report") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and 2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant. Date: February 28, 2005 /s/ Richard Sipes ---------------------- -------------------------------------------- Richard Sipes, Principal Executive Officer I, Michael Mascis, Principal Accounting Officer of UBS Multi-Strat Fund, L.L.C. (the "Registrant"), certify that: 1. The Form N-CSR of the Registrant (the "Report") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and 2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant. Date: February 28, 2005 /s/ Michael Mascis ---------------------- -------------------------------------------- Michael Mascis, Principal Accounting Officer (principal financial officer) THIS CERTIFICATE IS FURNISHED PURSUANT TO THE REQUIREMENTS OF FORM N-CSR AND SHALL NOT BE DEEMED "FILED" FOR PURPOSES OF SECTION 18 OF THE SECURITIES EXCHANGE ACT OF 1934, OR OTHERWISE SUBJECT TO THE LIABILITY OF THAT SECTION, AND SHALL NOT BE DEEMED TO BE INCORPORATED BY REFERENCE INTO ANY FILING UNDER THE SECURITIES ACT OF 1933 OR THE SECURITIES EXCHANGE ACT OF 1934.