Breakthroughs - of a sort - were achieved on Thursday in three disputes affecting General Motors operations in the US while a new deal has been agreed with a key Canadian union.

GM spokesman Dan Flores told the Associated Press (AP) the automaker had agreed a deal with a local United Auto Workers union branch that could end a strike which began on 17 April at the Delta Township plant near Lansing, Michigan, that makes the hot-selling Buick Enclave, Saturn Outlook and GMC Acadia crossovers.

The 3,300 affected workers will remain on strike until the contract is ratified, the report said, adding that Flores was unable to say when the vote would take place.

The Detroit News reported that GM had cancelled the medical and life insurance benefits of workers on strike at the factory while the UAW was paying medical costs for workers who turned up for picket line assignments, as well as for their families. Strikers, however, were to get no dental or vision coverage.

The newspaper said GM last cancelled benefits for workers on a picket line during the crippling Flint (Michigan) strikes of 1998.

The report said GM made the move after a factory in Ontario, Ohio, backed out of a strike threat that was scheduled for 10am Thursday (15 May). That plant stamps metal and employs about 1,400 hourly workers.

Flores told Automotive News that UAW Local (branch) 549 withdrew the strike threat on Wednesday afternoon, and that GM is continuing to bargain with the union.

That plant employs about 1,400 workers, according to AP.

The striking Delta Township workers stopped receiving benefits from GM from midnight Wednesday, GM's Flores told the Detroit News.

The paper noted that the UAW's national contract with GM allows the automaker to cancel benefits on the first of the month following a walkout and, under this provision, GM could have cancelled the benefits as early as 1 May.

Meanwhile, Reuters reported from across the border that the Canadian Auto Workers union (CAW) and GM of Canada have reached a tentative agreement on terms for a new contract after bargaining throughout last night.

"We have a tentative agreement with GM," CAW spokeswoman Shannon Devine told the news agency.

Talks with privately held Chrysler are continuing, Devine told Reuters, which said the terms of the proposed GM contract were not immediately available.

According to the report, CAW president Buzz Hargrove had said late on Wednesday that he expected to reach new contract agreements with both automakers by Thursday that would follow the pattern set by a now-ratified three-year deal with Ford. The bargaining affects contracts for over 22,000 Canadian auto workers at GM and Chrysler.

Reuters said part of the CAW deal with GM will include buyout and early retirement offers for some 1,200 union-represented workers at the Windsor, Ontario, transmission plant GM will close in 2010.

GM announced plans to close that 45-year-old plant on Monday, a decision Hargrove said had come as a shock although union leaders have also said they believe dwindling market share left GM with no other choice.

Hargrove told Reuters on Wednesday night that the two sides had reached a "close-out" agreement for the Windsor plant.

The CAW's current contracts with GM and Chrysler do not expire until 16 September. The three-year Ford contract, covering about 9,000 workers, reportedly freezes base wages, cuts a week of holidays and avoids any cost of living pay increases until the end of 2009 but avoids the two-tier wage system the Detroit automakers have instituted in their US factories, the news agency said.

GM restores some strike-hit production