Standard & Poor’s lowered B of A’s debt ratings.

The agency said the downgrading affects about $4 billion of outstanding debt securities and $2 billion of shelf registrations of BankAmerica, parent of Bank of America. S&P; said it took the action because of the bank’s heavy loan losses and continuing problem loans in agriculture, real estate, shipping and to developing countries. Downgraded were B of A senior debt to A- from A+, subordinated debt to BBB+ from A, preferred stock to BBB- from A- and commercial paper to A-2 from A-1. Debt supporting the bank’s letters of credit was cut to A- from A+, and debt supporting commercial paper was cut to A-2 from A-1. Seafirst Corp.’s senior debt and some Seattle First National debt was cut to BBB from A-. The bank said it disagreed with the S&P; move and was taking steps to deal with its loan losses.