CERTIFICATION PURSUANT TO RULE 30A-2(B) UNDER THE 1940 ACT AND SECTION 906 OF THE SARBANES-OXLEY ACT I, Douglas Lindgren, 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: March 8, 2007 /s/ Douglas Lindgren -------------------- ----------------------------------------------- Douglas Lindgren, Principal Executive Officer (principal executive officer) I, C. Philip Tazza, 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: March 8, 2007 /s/ C. Philip Tazza -------------------- ----------------------------------------------- C. Philip Tazza, Principal Accounting Officer (principal financial officer)