Specifics of the agreement were withheld until the proposal is ratified by union members over the next several weeks, Amtrak, the nation's quasi-government passenger rail corporation, said.

The contract is believed to follow recommendations of a presidential emergency board on Dec. 30 in which Amtrak was urged to grant back wages to its workers, the Wall Street Journal reported.

"We have averted a possible strike that could have had a crippling effect on the lives of millions of Americans," Alex Kummant, Amtrak president and chief executive said in a statement.

There has never been a strike in Amtrak's 36-year history.