Contract talks between Ford Motor Co and the United Auto Workers union broke off in the early hours of Wednesday morning after a marathon session that began Tuesday morning, a source familiar with the talks said.
The negotiations for a new four-year contract were expected to resume later Wednesday.
Contract talks between Ford and the UAW for its 58,500 Ford members have picked up pace this week, after the union wrapped up deals with General Motors Corp and Chrysler LLC.
Negotiations intensified on Tuesday, with some activity expected in the next two days, a person familiar with the talks said on Tuesday.
The person, who asked to not be identified due to the confidential nature of the talks, declined to say if the activity within the next 48 hours would be a strike or settlement.
A Ford spokeswoman declined to comment on the talks. A UAW spokesman did not return calls for comment.
Another person familiar with the talks said UAW President Ron Gettelfinger on Tuesday joined other negotiators at the bargaining table -- a sign talks were moving to their final stage.
Ford and the union have been in talks constantly for the past few months, the UAW's chief negotiator for Ford, Bob King, said earlier this month.
He also said the union was looking for the same things in the contract that it sought from GM and Chrysler, such as product investment and retiree healthcare.
Working-level negotiators from Ford and the UAW even met at the automaker's Dearborn, Michigan, headquarters over the weekend.
But bargaining on some of the main issues between Ford and the union had not begun before Tuesday since the union leadership, including Gettelfinger, has so far remained focused on the final ratification votes on a tentative labor contract with Chrysler.
Both sides have expressed eagerness to wrap up talks without a strike -- unlike GM and Chrysler, both of which underwent strikes before a tentative deal.
Still, some locals have been preparing workers for a possible strike. UAW Local 2000, which represents 2,050 active workers at an Ohio assembly plant, has assigned picket captains and posted strike instructions on its Web site.
Members of local 245, which represents more than 2,500 workers at various facilities in Dearborn, Michigan, have also been preparing for a strike.
Ford, widely seen as the weakest of the three embattled U.S. automakers, has already made it clear that it will push for deeper concessions from the union than those offered by GM or Chrysler, a position negotiators made clear in early talks.
In addition, Ford has indicated it was looking for about 8,000 to 10,000 additional factory job cuts, one of those briefed on the negotiations said. That would be in addition to the 27,000 UAW jobs Ford had cut as of June.
The automaker, which posted a record loss of $12.6 billion in 2006, has announced plans to close 16 plants as part of its restructuring in North America, although it has not named six of those facilities.
Both sides have said they intend to keep the basic framework of the deals reached with GM and Chrysler.
Both settlements established a trust known as a Voluntary Employees Beneficiary Association, or VEBA, that would take over responsibility for retiree health care.