Prospectus excerpt:  Each trust preferred security represents a corresponding amount of the company preferred securities and related rights under the UBS AG subordinated guarantee. Dividends and redemption and liquidation payments paid by UBS Preferred Funding Company on the company preferred securities will pass through UBS Preferred Funding Trust to you as distributions and redemption and liquidation payments on the trust preferred securities.

The company preferred securities will pay monthly distributions on the first business day on or after the 15th day of each month, commencing in June 2003 at a floating rate per annum equal to .70% above one-month LIBOR. The company preferred securities are perpetual securities and do not have a maturity date. UBS Preferred Funding Company may redeem the company preferred securities on or after the dividend payment date in June 2008.

The company preferred securities provide holders with rights to distributions and redemption and liquidation payments that are similar to those of the most senior ranking noncumulative perpetual preferred shares that could be issued directly by UBS AG with financial terms equivalent to those of the company preferred securities.

UBS AG will guarantee, on a subordinated basis, dividend, redemption and liquidation payment obligations under the company preferred securities.