The US Federal Reserve Monday authorized giving credit card giant American Express full status as a bank holding company.

The US central bank said that both American Express Company and its affiliate American Express Travel Related Services would be allowed to form bank holding companies, as the AMEX group converts its Salt Lake City, Utah-based American Express Centurion Bank into a full commercial bank.

"In light of the unusual and exigent circumstances affecting the financial markets, and all other facts and circumstances, the (Federal Reserve) Board has determined that emergency conditions exist that justify expeditious action on this proposal," the Fed said in a statement.

AMEX, with 127 billion US dollars in consolidated assets, will convert the Centurion Bank, which is classified as a limited industrial loan company with about 25.3 billion US dollars in assets, into a full bank.

The move comes four days before a US Treasury deadline for banks to participate in its 700 billion dollar bank rescue program to provide US banks with additional capital amid turmoil in US financial markets.