UBS DYNAMIC ALPHA FUND

                 SUPPLEMENT TO PROSPECTUS DATED OCTOBER 28, 2004

                                                                 August 23, 2005

Dear Investor,

   The following supplements information contained in the Prospectus section
   titled "Managing Your Fund Account":

   THE SUB-HEADING "CLASS Y SHARES" IS DELETED IN ITS ENTIRETY AND REPLACED BY
   THE FOLLOWING:

   Shareholders pay no front-end sales charges on Class Y shares. However, as of
   May 26, 2005, UBS Global AM, as principal underwriter of the Funds, may make
   payments out of its own resources, to affiliated (UBS Financial Services
   Inc.) and unaffiliated dealers, pursuant to written dealer agreements as
   follows: a one time finder's fee consistent with the Fund's Class A share
   Reallowance to Selected Dealers' schedule (see page 10) and beginning in
   month 13 an ongoing fee in an amount up to 20 basis points. UBS Global AM
   does not make these payments on employee related Class Y share accounts and
   reserves the right not to make these payments if it determines, in its sole
   discretion, that a dealer has been acting to the detriment of the Fund.

   The following are eligible to purchase Class Y shares:

     -  Shareholders of Class I shares of any UBS Fund who held such shares as
        of the date the shares were redesignated Class Y shares;

     -  Retirement plans with 5,000 or more eligible employees or $100 million
        or more in plan assets;

     -  Retirement plan platforms/programs that include Fund shares if the
        platform/program covers plan assets of at least $100 million;

     -  Trust companies and bank trust departments purchasing shares on behalf
        of their clients in a fiduciary capacity;

     -  Banks, registered investment advisors and other financial institutions
        purchasing fund shares for their clients as part of a discretionary
        asset allocation model portfolio;

     -  Shareholders who owned Class Y shares of the Fund through the PACE
        Multi-Advisor Program as of November 15, 2001, will be eligible to
        continue to purchase Class Y shares of that fund through the program;

     -  College savings plans organized under Section 529 of the IRC, if
        shareholder servicing fees are paid exclusively outside of the
        participating funds;

     -  Other investors as approved by the Funds' Board of Trustees;

     -  Shareholders who invest a minimum initial amount of $5 million in the
        Fund. An institutional investor may aggregate its holdings with holdings
        of certain related institutional investors to meet the foregoing
        minimums;

     -  Foundations, Endowments and Religious and other charitable organizations
        described in Section 501(c)(3) of the IRC that invest a minimum initial
        amount of $2,500,000 in the Fund; and

     -  Employees of UBS Global AM as long as the employee is named on an
        account purchased direct from the Funds' transfer agent in the minimum
        initial amount of $50,000.

     Class Y shares do not pay ongoing 12b-1 distribution or service fees. The
     ongoing expenses for Class Y shares are the lowest of all the classes.

                                                                 Item No. ZS-270