Based on article 20 of the Federal Act on Stock Exchanges and Securities Trading (SESTA) UBS AG, Bahnhofstrasse 45, 8098 Zurich, makes the following announcement:

As of 29 February 2008 UBS AG held a stake of 5.73% of acquisition positions (proportion of voting rights) of registered shares of UBS AG. These comprised 104,858,252 (5.06%) registered shares of UBS AG with voting rights and 6,831,700 acquisition rights with 6,831,700 (0.33%) voting rights and 7,222,589 written disposal rights with 7,222,589 (0.34%) voting rights of registered shares of UBS AG.

At the same time UBS AG held a stake of 25.97% (538,431,438) disposal positions (proportion of voting rights) of registered shares of UBS AG. These comprised 9,270,655 disposal rights with 9,270,655 (0.45%) voting rights of registered shares of UBS AG and 529'160'783 written acquisition and convertible rights with 529'160'783 (25.52%) voting rights of registered shares of UBS AG.

UBS directly and indirectly holds the acquisition and disposal positions through the following companies:

UBS Convertible Securities (Jersey) Limited, 24 Union Street, St. Helier JE2 3RF, Jersey.

UBS Global Asset Management Holding (No. 2) Ltd, 21 Lombard Street, London EC3V 9AH, United Kingdom (indirectly through UBS Global Asset Management Holding Ltd, 21 Lombard Street, London EC3V 9AH, United Kingdom, indirectly through UBS Global Asset Management (UK) Ltd, 21 Lombard Street, London EC3V 9AH, United Kingdom) and (indirectly through UBS Global Asset Management Holding Ltd, 21 Lombard Street, London EC3V 9AH, United Kingdom, indirectly through UBS Global Asset Management Life Ltd, 21 Lombard Street, London EC3V 9AH, United Kingdom) and

UBS Wealth Management (UK) Ltd, 1 Finsbury Avenue, London EC2M 2PP, United Kingdom and

UBS O'Connor LLC, c/o National Corporate Research Ltd, 9 East Loockerman St, Dover DE 19901, USA and

UBS Americas Inc., 2711 Centerville Road Suite 400, Wilmington 19808, Delaware, USA (indirectly through UBS Global Asset Management (Americas) Inc., The Corporation Trust Company, Corporation Trust Center, 1209 Orange Street, Wilmington DE 19801, Delaware, USA) and (indirectly through UBS Securities LLC, 2711 Centerville Road, Wilmington DE 19808, Delaware, USA) and (indirectly through UBS AM Holdings (USA) Inc., c/o The Corporation Trust Company, Corporation Trust Center, 1209 Orange Street, Wilmington DE 19801, Delaware, USA, indirect through UBS Global Asset Management (Canada) Co., 600 de Maisonneuve Boulevard West, Suite 2710, Montreal H3A 3J2, Quebec, Canada) and (indirectly through DSI International Management Inc., Corporation Service Company, 2711 Centerville Road, Suite 400, Wilmington 19808, New Castle / DE, USA) and (indirectly through UBS Financial Services Inc., Corporation Service Company, 2711 Centerville Road, Suite 400, Wilmington 19808, Delaware, USA) and

UBS Beteiligungs-GmbH & Co KG, Stephanstrasse 14 - 16, 60313 Frankfurt am Main, Germany (indirectly through UBS Global Asset Management (Deutschland) GmbH, Stephanstrasse 14 - 16, 60313 Frankfurt am Main, Germany) and

UBS International Holdings BV, Herengracht 600, 1017 CJ Amsterdam, Netherlands (indirectly through UBS Holding (France) SA, 65 Rue de Courcelles, 75008 Paris, France, indirectly through UBS Global Asset Management (France) SA, 69 Boulevard Haussmann, 75008 Paris, France) and (indirectly through UBS Holding (France) SA, 65 Rue de Courcelles, 75008 Paris, France, indirectly through Caisse Centrale de Réescompte, 44 Rue Washington, 75008 Paris, France) and

UBS (Luxembourg) S.A., 33a Avenue J.F. Kennedy, 1855 Luxembourg, Luxembourg (directly and indirectly through UBS Belgium SA/NV, Avenue de Tervueren 300, Woluwe-Saint-Pierre, 1150 Bruxelles, Belgium) and

UBS (Bahamas) Ltd., UBS House, East Bay Street, Nassau, Bahamas and

UBS Global Asset Management (Hong Kong) Ltd, 46-52 Floors Two International Finance Centre, 8 Finance Street, Central, Hong Kong and

UBS Global Asset Management (Australia) Ltd, Leven 7, Chifley Tower, 2 Chifley Square, Sydney NSW 2000, Australia.

This disclosure is being made pursuant to the simplification of the reporting requirements through the Disclosure Office of the SWX Swiss Exchange. Details about the required disclosure of the acquisitions and the disposal positions will be provided on demand and free of charge (contact: UBS Investor Relations, +41-44-234 41 00) via e-mail, fax or mail.