FINANCIAL CORP <FIN> UNIT BUYS BRANCHES Financial Corporation of America's American Savings and Loan Association unit said it signed a definitive agreement to buy three retail savings branches from Gibraltar Financial Corp's <GFC> Gibraltar Savings unit. The purchase, which must be approved by the Federal Home Loan Bank and the California Department of Savings and Loans, would increase American Savings' deposits by about 40 mln dlrs. The branches are in La Jolla, La Mesa and San Juan Capistrano, Calif.