Frankfurt  - On the fifth day of rolling strikes in Germany's most important factories, the IG Metall trade union said it would rule next Tuesday on whether to escalate the wage battle into an all-out strike.

An Opel car plant owned by General Motors west of Frankfurt was idled on Wednesday for hours as 6,000 workers attended a rally outside the gates to support IG Metall's demand for an 8-per-cent pay hike.

Stoppages, being held in relays round the country, hit many other auto industry plants. Each day, the union aims to raise the pressure, but a strike in all plants at the same time has not begun yet.

A total of 162,000 workers had stopped work on Tuesday, IG Metall said at day's end, but offered no Wednesday tally.

The union has rejected an offer of 2.1 per cent more pay for 3.6 million industry workers, accusing the employers of "utter cheek."

The timing of the union's next move is constrained by German labour law. Metal-products and electrical-goods employers will have till Tuesday to persuade the union to accept a pay offer.

Berthold Huber, the union leader, said that the union leadership would meet immediately after the scheduled pay bargaining meeting with employers on Tuesday and decide whether or not to launch an all-out, open-ended strike.

"Either there'll be a deal or there'll be a labour struggle," he told Deutsche Presse-Agentur dpa.

"I am not dead set on a strike. We just want a fair and sustainable settlement," he said, rejecting the employers' offer as less than the rate of inflation.

But addressing 6,000 union members outside a Volkswagen-owned Audi plant at Neckarsulm, north of Stuttgart, he said, "We are all ready to strike."

He did not say when a strike might begin, but told the crowd the legally required poll among members on whether to hold an all-out strike could be carried out in just two or three days. (dpa)