Ford Motor Co on Saturday said it had reached a tentative labor deal with the United Auto Workers union, capping a historic round of bargaining between the union and the embattled U.S. auto industry.

Ford, the last of Detroit's Big Three automakers to reach a contract, said the tentative four-year deal includes the establishment of an independent health care trust for retirees, but declined to disclose any more details.

The deal, reached early on Saturday morning, came after an extended marathon bargaining session of more than 40 hours, which had begun at around 10 a.m. EDT on Thursday.

The contract is now subject to ratification by Ford's roughly 58,000 UAW-represented workers.