WARREN, Mich. (AP) -- General Motors Corp. dodged one strike at a key factory on Friday, but the United Auto Workers threatened to walk out at the main plant that builds the hot-selling Chevrolet Malibu.

UAW Local 31 at the Malibu factory in Fairfax, Kan., near Kansas City, on Thursday gave the company a letter warning that it will strike the plant in five days if local contract issues go unresolved, GM spokesman Dan Flores said Friday.

The strike would hurt GM financially because the Malibu is selling well even as U.S. auto sales slump. The company has only a 37-day supply of the mid-sized sedan, according to Wards AutoInfoBank.

"We're going to continue the bargaining at Fairfax," Flores said. "Our focus is on reaching a new local agreement there as soon as we can."

A message seeking comment was left for Local 31 President Jeff Manning.

Five-day strike notices typically are five business days, meaning the plant could go on strike as early as Thursday.

The notice came as GM avoided - at least for now - a threatened strike at a key transmission plant in Warren. A strike deadline passed Friday morning with union workers remaining on the job as both sides agreed to keep bargaining.

The Warren factory makes four- and six-speed transmissions for nearly all of GM's cars. If the strike had occurred, it could have crippled the automaker's car production.

Members of the United Auto Workers Local 909 at the Warren powertrain plant had set a 10 a.m. deadline to leave their jobs in a local contract dispute.

But plant worker Damion Morris said the union decided to postpone the walkout for another 24 hours. If Local 909 sets another strike deadline, it will give GM a 12-hour notice, he said.

Flores said negotiators worked through the night and decided to return to the table on Saturday morning.

"Your bargaining committee, along with the regional and international union, are pleased to report that progress has been made in the last several hours of negotiations," Local 909 officers said in a letter distributed to workers on Friday. "As a result of this development UAW-GM Vice President Cal Rapson has authorized an extension of the five-day strike letter.

"The time for this extension is dependent upon the movement of the talks. Should talks stall, or become unsatisfactory, then Vice President Cal Rapson will invoke a 12-hour notice," the letter said. "Should this notice be authorized the clock will begin ticking."

Workers at a crossover vehicle factory near Lansing walked off their jobs on Thursday.

Industry analysts say the union is using the threats of a strike to pull GM into an ongoing labor dispute at parts maker American Axle and Manufacturing Holdings Inc. The UAW has been on strike against American Axle for nearly two months, and more than 30 GM plants have been affected.

On Thursday, members of UAW Local 602 walked out of the GM plant in Delta Township that makes the Buick Enclave, Saturn Outlook and GMC Acadia large crossover vehicles.

Local plants negotiate their own operating agreements separate from the national contract, which was settled last year. The local contract deals with issues such as overtime and work rules.

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