Geoff Yost

Partner

Geoffrey Yost is a partner in O’Melveny’s San Francisco office and a member of the Intellectual Property and Technology Practice within the Litigation Department.  Geoff has 19 years of commercial litigation experience.  His practice emphasizes complex, high-stakes technology litigation, particularly multi-party, multi-forum patent and antitrust actions involving the semiconductor industry.  Geoff also has an extensive environmental litigation background and is a member of the Energy, Natural Resources, and Environment Practice.  He represents businesses in cost recovery actions, disputes arising from contaminated real estate, citizen suits, and multiparty Superfund Site litigation and cleanups.

Illustrative Professional Experience

• Representing a major multinational semiconductor manufacturer in multiple patent and antitrust actions against a high-profile computer memory interface technology firm 
• Defending a major multinational semiconductor manufacturer in Cartwright Act action in California state court brought by Texas semiconductor packaging technology firm
• Litigated and settled international arbitration for software development firm following acquisition of Canadian software development partnership
• Litigated and settled software development contract dispute between software engineering consulting firm and its client
• Litigated numerous federal and state law cost recovery lawsuits in federal and state courts on behalf of landowners, manufacturers, a major railroad, and energy companies
• Counseled major utility in natural resource issues and defended it in natural resource litigation against a California water district
• Successfully defended major bank in a dispute over contaminated real estate through appeal, recovering attorneys’ fees
• Successfully defended California petroleum company in Clean Water Act citizen suit through appeal
• Represented renewable energy company and dry cleaner franchise in administrative proceedings before the Hearing Board of the South Coast Air Quality Management District
• Successfully defended petroleum distributor and its employee against allegations of trade secret theft, obtaining dismissal on summary judgment
• Successfully pursued asset purchaser in breach of contract and fraudulent transfer action through appeal, recovering fees
• Defended multiple companies against Proposition 65 claims, including a furniture maker, dry cleaners, retail store, home products distributor, and construction company
• Advised a major consumer product testing company regarding its Proposition 65 compliance testing services

Professional Activities

Extern,  California Supreme Court (1990)
Admitted to Practice,  US District Court, Central, Eastern, Northern, and Southern Districts of California, US Court of Appeals, Ninth Circuit; US Court of Federal Claims
Member,  San Francisco Bar Association
Adjunct Professor,  University of California, Hastings College of Law (1998)
Editorial Board,  Environmental Liability, Enforcement and Penalties Reporter (2000-2008)