NEW YORK — Moody’s Investors Service has lowered Bank of America Corp.’s debt ratings, saying it is now less likely that the U.S. government would step in and prevent the lender from failing in a crisis.

The ratings firm said Wednesday that it believes the government is likely to provide some level of support for financial institutions, but is also more likely now than during the 2008 financial crisis to allow a large bank to fail should it become financially troubled.

Moody’s downgraded BofA’s long-term debt rating two notches to investment-grade “Baa1″ from “A2″ and to Prime-2 from Prime-1 for short-term debt.

It also cut Bank of America N.A.’s long-term deposit ratings to “A2″ from “Aa3.”

Bank of America shares were down 38 cents, or 5.5 percent to $6.52 in afternoon trading.