B of A May Buy Half of Skyscraper: BankAmerica Corp. has entered an agreement with Shorenstein Co. that will allow it to eventually buy back 50% of its 52-story headquarters complex, which was sold in 1985 when the bank was facing financial difficulties. “It’s an agreement on an option and if exercised would be several years in the future,” said John Keane, a B of A spokesman. “It’s fair to conclude that circumstances have changed since 1985,” said Keane of the deal in which developer Walter H. Shorenstein bought the bank’s skyscraper and two other buildings of historical significance for $660 million. At the time, the deal was considered the country’s biggest real estate transaction. Details on the price of the option agreement were unavailable.