CERTIFICATION
                             Pursuant to Section 906
                        of the Sarbanes-Oxley Act of 2002


         The undersigned, the Chief Executive Officer of Old Mutual Absolute
Return Master Fund, L.L.C. (the "Fund"), with respect to the Fund's Form N-CSRS
for the period ended September 30, 2007 as filed with the Securities and
Exchange Commission (the "Commission"), hereby certifies, pursuant to 18 U.S.C.
Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of
2002, that, to the best of my knowledge:

         1. such Form N-CSRS fully complies with the requirements of section
13(a) or 15(d) of the Securities Exchange Act of 1934; and

         2. the information contained in such Form N-CSRS fairly presents, in
all material respects, the financial condition and results of operations of the
Fund.


Dated: December 4, 2007


                                             /s/ William J. Landes
                                             ---------------------
                                             William J. Landes
                                             President & Chief Executive Officer



A signed original of this written statement required by Section 906 has been
provided to the Fund and will be retained by the Fund and furnished to the
Commission or its staff upon request.