<PAGE>
EXHIBIT 12(e)
CERTIFICATE OF HOLDER OF BENEFICIAL INTERESTS
Mercury Asset Management US, a division of Fund Asset Management,
L.P., the holder of the beneficial interests in the amount of $100 of Mercury
Master Select Growth Portfolio of Mercury Asset Management Master Trust (the
"Trust"), does hereby confirm to the Trust its representation that it purchased
such shares for investment purposes, with no present intention of redeeming or
reselling any portion thereof.
Mercury Asset Management US, a division of
Fund Asset Management, L.P.
By: Princeton Services, Inc.,
General Partner
By: /s/ Terry K. Glenn
------------------------------------------
Name: Terry K. Glenn
Title: Executive Vice President and
Director
Dated: June 13, 2000