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 5, 2008 /s/ Douglas Lindgren ------------- -------------------------------------------------- Douglas Lindgren, Principal Executive Officer I, Robert Aufenanger, Principal Financial 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 5, 2008 /s/ Robert Aufenanger ------------- -------------------------------------------------- Robert Aufenanger, Principal Financial Officer