On Sunday, the UAW union gave Chrysler a 72-hour notice of a potential strike, reports said, adding, it was unclear exactly whether the notice would end on Tuesday or Wednesday.

Chrysler''s previous agreement had been extended since 14 September while the UAW concentrated on talks with General Motors. On 26 September, GM and the union reached a settlement.

On 6 Ocober Chrysler, acquired by owned by Cerberus Capital Management LP from DaimlerChrysler (See: DaimlerChrysler, Cerberus complete Chrysler deal), received a 72-hour notice that the union is terminating further extensions, after which a strike is possible, the reports said.

The UAW had used a similar strategy in talks with GM before staging a two-day nation-wide strike, its first at America''s top automaker in 37 years. GM later signed a tentative agreement with the UAW. (See: General Motors workers strike work)

The union seems to be using its tactics before the GM agreement as a pattern for negotiations with Chrysler and Ford Motor Co. However, the two automakers have said their needs are different from GM''s and may need altogether different deals.

The notice is likely to be a pressure tactics aimed at a quick settlement and need not necessarily mean there will be a strike. The union could extend its contract when the deadline passes.

Bargainers working in committees made progress during the weekend but still have much work to do on difficult issues, sources said.

Chrysler, meanwhile, has planned a weeklong shutdown at its five US plants starting Monday because of lower market demand for their vehicles