Strikes in eastern Germany may force BMW to re-evaluate its level of investment in the city of Leipzig, where it is building a new factory.
The Leipzig plant, due to open in 2005, will build the 3 series and possibly the coming 1 series. BMW said the factory would create 5,000 jobs.
"It was the goal to create as many jobs as possible in eastern Germany. We must now reconsider this," said Ernst Baumann, BMW's head of personnel.
"BMW chose Leipzig for patriotic reasons but is now regretting its decision," said Hans-Werner Sinn, president of Germany's Ifo economic institute.
BMW said it would resume production of the 3 series today (June 30) after a strike at transmission systems supplier ZF Friedrichshafen's Brandenburg plant in eastern Germany was temporarily ended.
BMW makes 850 units a day of the 3 series at Regensberg and another 800 units daily at Munich. Production was stopped on June 23.
The suspension of the ZF strike was a conciliatory move by German engineering union IG Metall, which wants to cut the working week in eastern Germany by three hours to western Germany's 35 hours.
Now BMW is planning to protect itself from the effects of strikes outside Bavaria.
"The whole supply chain will be examined," a BMW manager told German sister publication Automobilwoche. "IG Metall has opened a Pandora's Box."
-- Automobilwoche and Reuters News Service contributed