Wesco Financial Corp., an insurance and steel holding company based in Pasadena, agreed to buy Cort Business Services Corp., which rents furniture, for $384 million in cash. A subsidiary of Wesco, which is 80% owned by Warren Buffett's Berkshire Hathaway Inc., will pay $28 a share in cash for Cort and assume $83 million in debt. Shares in Cort closed up 38 cents at $17.13 on the NYSE. In November, Fairfax, Va.-based Cort said it and an investor group canceled the group's planned $458-million buyout because of "insufficient" shareholder support. Cort operates 278 furniture showrooms, clearance centers and warehouses in 34 states and Washington, D.C. "Cort is the kind of 'best in class' business that . . . I like to add to the Berkshire group of companies," Buffett said in a statement. Cort's board unanimously approved the transaction. The tender offer will start Jan. 24. Wesco shares fell $3 to close at $270 on the American Stock Exchange, and Berkshire Hathaway's Class A shares fell $2,200 to close at $52,200 on the NYSE. The purchase was announced after the markets closed.