NEW YORK: Moody's Investors Service on Thursday downgraded the debt of four big bank holding companies, including Morgan Stanley and JPMorgan Chase & Co, after concluding that the government is less likely to bail out their bondholders in the future.

Moody's cut long-term debt ratings by one notch for the banks, which also included Goldman Sachs Group Inc and Bank of New York Mellon Corp.

The service confirmed senior holding company ratings for Bank of America Corp, Citigroup Inc, State Street Corp and Wells Fargo & Co.

U.S. bank regulators have made substantive progress in creating credible plans to end taxpayer bailouts of too-big-to-fail banks, Moody's Managing Director Robert Young said in a statement.

The rating service said creditors of bank holding companies are now more likely to suffer losses and shoulder much of the burden of salvaging a failing bank.

Representatives of Bank of New York Mellon, Goldman Sachs and JPMorgan declined to comment. A Morgan Stanley spokesman had no immediate comment.