May 17 (Reuters) - Berkshire Hathaway Inc said on Monday it has taken a $943 million stake in the insurance company Aon Plc and nearly dissolved a more than three-decade-old investment in Wells Fargo & Co. The changes were disclosed in a regulatory filing detailing Berkshire’s U.S.-listed holdings in its $282.1 billion equity portfolio as of March 31. Berkshire said it owned just $26.4 million of Wells Fargo stock. It once owned around $32 billion worth of shares in the fourth-largest U.S. bank. (Reporting by Jonathan Stempel in New York; editing by Jonathan Oatis) Our Standards: The Thomson Reuters Trust Principles.