Paul Hastings Represents Micromuse in $865 million Acquisition by IBM

December 27, 2005

Paul, Hastings, Janofsky & Walker LLP (Paul Hastings) represented San Francisco-based Micromuse Inc. in its acquisition by International Business Machines Corp. for approximately $865 million in cash. The deal was announced on December 20, 2005 and is expected to close in the first quarter of 2006. The Paul Hastings team was led by Los Angeles partner Rob Carlson and San Diego partner Carl Sanchez. Rob and Carl were assisted by San Diego partner Deyan Spiridonov, Washington, D.C. partner Mark Poerio, London partners Joel Simon and Nigel Heilpern, Orange County partner Alexander Lee and associates Claudia Simon, Stephen Lee, Daphne Tam, Kevin OSullivan, Lynda Noggle and Ronan OSullivan. About Micromuse, Inc.: Micromuse Inc. (Nasdaq: MUSE), headquartered in San Francisco, Calif., is the leading provider of ultra-scalable, realtime business and service assurance software solutions. The Netcool software suite provides organizations with the assurance that their IT systems are supporting and driving the achievement of business objectives. Netcool solutions provide realtime, end-to-end visibility and accurate troubleshooting from a business perspective, allowing organizations to respond to problems quickly, streamline workflow processes, and improve business uptime. For more information, call (415) 568-9800, or visit their website at www.micromuse.com. Paul Hastings Janofsky & Walker LLP, founded in 1951, is a leading international law firm with 1,000 attorneys in 17 offices. The firm serves a diverse client base including many of the top financial institutions and Fortune 500 companies, supports clients in all of their legal needs and offers deep capabilities in Banking and Finance, Capital Markets, Corporate/M+A, Litigation and Dispute Resolution, Intellectual Property, Project Finance, Investment Management, Real Estate, Labor and Employment and Tax Advisory Services. For additional information, please visit our website at www.paulhastings.com.