BERLIN -- A huge German industrial union said on Thursday it would hold a ballot on an all-out strike at the end of February unless it reaches a pay deal with employers by then.
The announcement from IG Metall's deputy leader Berthold Huber came as its members began a second week of short protest strikes and pay talks resumed.
"Either we have a deal by then or we will have to prepare for industrial action," Huber told the Berliner Zeitung.
Economists say an all-out strike by IG Metall, which represents 3.5 million workers in engineering and manufacturing, could dent a nascent recovery in Europe's largest economy and hurt its chances of attracting much-needed investment.
IG Metall has been calling brief stoppages at German companies, including household names in the car industry, to push its claim for a four percent pay rise and protest against employer demands for more flexible working hours.
On Thursday, it called on 30,000 workers in the state of North Rhine-Westphalia, home to the industrial Ruhr region, to down tools at 290 firms, including at industrial and engineering group ThyssenKrupp.
In the south-western state of Baden-Wuerttemberg, IG Metall called on workers at 55 firms to walk out, including at auto components firm Robert Bosch.
IG Metall called a demonstration at carmaker DaimlerChrysler AG's Rastatt plant and said it expected 2,000 workers to protest outside the pay talks in Boeblingen, near Stuttgart.
The stoppages were due as it met employers in Baden-Wuerttemberg, the state which typically leads negotiations for the rest of Germany.
Talks also resume in Bavaria, where carmaker BMW is based. Both sides have said talks this week are unlikely to settle their differences over wages and working hours.
Several rounds of talks in regions across Germany are planned this month. The union says it will decide on its future strategy in the coming days and will continue with its campaign of limited stoppages, a typical feature of German pay rounds.
IG Metall has rejected an offer from employers of two separate rises of 1.2 percent over 27 months coupled to changes to rules on working hours which it says will result in longer working hours and hence lower pay.
Employers' federation Gesamtmetall says more flexible hours would allow firms to remain competitive and avoid cutting jobs.
"We want working councils and managers to act in certain situations to stop wages dropping and jobs being lost," the group's president Martin Kannegiesser told German television.
But Germany's largest union, the Verdi services group, said it backed IG Metall's refusal to alter working hour regulations. "We want to save jobs, at least for a while," Verdi deputy, Margret Moenig-Raane told French daily La Tribune.