San Francisco U.S. District Judge Charles Legge gave preliminary approval to a $19 million settlement of a 4-year-old class action lawsuit accusing BankAmerica Corp. of improperly putting trust funds into risky real estate investments. Plaintiff Frederick Fisher, acting on behalf of some 1,500 trust customers of Security Pacific National Bank, bought by BofA in 1992, charged the bank with channeling trust assets into high-risk real estate limited partnerships in order to generate sales commisions. The bank denied wrongdoing and said the investments were prudent.