No deal yet as the UAW and Fiat Chrysler Automobiles continued to negotiate through the night after extending the existing collective agreement on an hour-by-hour basis in anticipation of signing a tentative agreement soon.

The pace of the talks slowed a bit in the predawn hours but a core group continued to soldier on. Full resumption of bargaining is expected to resume by midday.

The two sides agreed to extend the current four-year contract shortly after it expired Monday at 11:59 p.m. Initially some workers wanted to walk off the job at midnight, and some reportedly left their posts but returned on news that the contract had been extended.

On Sunday, UAW President Dennis Williams announced the choice of Fiat Chrysler as the lead company to set a pattern agreement on major monetary issues which General Motors and Ford will be asked to match. FCA CEO Sergio Marchionne cancelled plans to attend the Frankfurt auto show to be in Auburn Hills for the talks.

Negotiations continue at GM and Ford, but they have assumed a more back-burner status. And the threat of a strike was alleviated at the two companies when UAW leadership extended the Ford deadline Monday afternoon. General Motors followed suit at 9 p.m.

The extensions mean about 141,000 employees continue to work under the terms of the 2011 contract until further notice.

Trey Durant, who works for Fiat Chrysler’s Mopar parts division, was on the afternoon shift that ended at 1 a.m. Tuesday. When the clock struck midnight with no word from union leadership, “people were ready to go,” he said. ‘There are people who want to walk.”

He was among the veterans telling them to wait for word from Detroit where the talks had continued with no update.

Durant said he was told by Mopar colleagues in California that some left at midnight. On the UAW’s Facebook page some workers were saying they were unsure what to do and some were ready to walk of the job if instructed to do so.

The UAW has several options if it is unable to reach an agreement with the automaker. It could call a national strike; targeted strikes at key plants or continue to extend the contract. The company also could try to lock out employees and bring in replacement workers but that hasn’t been tried in the automotive industry in a long time.

So far, there has not been a call to strike from Solidarity House.

Some locals said they were making signs and strike preparations. All three companies have had the legal right to strike restored; GM and Chrysler gave up that right as part of bankruptcy restructuring in 2009.

Wildcat strikes are rare; the union membership tends to be disciplined.

“It is not that abnormal to go past the deadline,” said Art Schwartz, a former GM negotiator and president of Labor and Economics Associates in Ann Arbor.

Even with whispers earlier in the day that the two sides were not far from a settlement, from his experience at the table Schwartz  knows “they never ever settle early.”

“If they don’t get everything the members want, which you never do, you better go past the deadline or it looks like you didn’t do enough,” Schwartz said.

The other odd quirk of talks: agreements are never reached early in the day. “They are always in the middle of the night,” said the long-time negotiator.

The UAW’s selection of Fiat Chrysler as the lead target among the Detroit Three on Sunday was viewed as an odd choice by some because the union has typically selected the financially healthiest automaker and Fiat Chrysler’s profits have been the smallest of the three.

Kristin Dziczek, director of the labor and industry group at the Center for Automotive Research, said reaching a tentative deal with Fiat Chrysler first will help the UAW figure out how best to apply the contract to GM and Ford.

Fiat Chrysler already has the lowest overall labor costs of the Detroit Three because it has highest percentage of workers hired at the lower wage.

The automaker’s average hourly labor costs for wages and benefits is $47 per hour compared with $55 per hour at GM and $57 at Ford.

“They have to know where Fiat Chrysler ends up so they can figure out what the gap is going to be with the other two,” Dziczek said. “GM and Ford don’t want to keep operating over the next four years with a $10 disadvantage to Fiat Chrysler.”

Contact Alisa Priddle: 313-222-5394 or apriddle@freepress.com. Follow her on Twitter @AlisaPriddle

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