BankBoston Expected to Buy Robertson

BankBoston Corp. is expected to announce an agreement to buy the San Francisco-based investment bank BancAmerica Robertson Stephens as soon as today, sources said. BankBoston would probably pay more than $700 million for Robertson Stephens, with the bulk going to BankAmerica Corp. and the rest to keep key employees after the sale. Robertson Stephens, which sold itself to BankAmerica last year for $540 million, would give BankBoston, New England’s second-largest bank, a strong underwriting practice it could add to its corporate finance services. BankAmerica would keep the firm’s money-management unit. Robertson Stephens founder and Chairman Sanford Robertson, 67, is expected to retire and form a private investment management firm, sources said. He resigned from BankAmerica’s board last month. BankAmerica put its investment bank up for sale in April after agreeing to merge with NationsBank Corp., which owns Robertson’s cross-town rival, NationsBanc Montgomery Securities.