Negotiators for the United Auto Workers said early Thursday that they agreed to a new contract with the Fiat Chrysler US auto company to avert a possible strike by up to 40,000 workers.

A previous tentative four-year deal was rejected on October 1 by 65 percent of the 40,000 employees that the union represents at the Fiat Chrysler Automobiles' US unit.

These negotiations are followed closely because any agreement reached between the UAW and Fiat Chrysler will serve as a template in upcoming talks with General Motors and Ford, the other top US automakers.

"After a lengthy bargaining process, your UAW FCA National Bargaining Committee has secured significant gains in a proposed Tentative Agreement with FCA," the UAW said on its Facebook site late Wednesday (0430 GMT Thursday).

UAW negotiators had set a midnight Wednesday deadline to reach an agreement, and the union had threatened to strike at some or all of the Fiat Chrysler plants in the United States.

Details of the new agreement have not yet been made public.

The bargaining committee "unanimously voted to send the proposed Tentative Agreement to local union leaders who make up the union's UAW National Chrysler Council," the union's statement read.

The Council will meet in Detroit at 11 am Friday (1500 GMT) "to discuss and vote on the agreement."

If the Council approves the contract, then it will be submitted to a full membership vote.

The UAW has traditionally negotiated similar contracts with all three automakers to prevent their employers from suffering competitive disadvantages.

FCA was launched in 2014 after Italian automaker Fiat bought the third-largest US automaker.