FRANKFURT (Reuters) - Workers at Volkswagen's Osnabrueck plant, considered a possible target for closure under the German automaker's restructuring plans, are holding fresh warning strikes on Wednesday as part of regional protests over pay, the IG Metall union said.

It is the second time in as many weeks that workers at the site are on strike, reflecting growing tension over Volkswagen's efforts to cut costs and potentially close factories in Germany for the first time.

While strikes at Volkswagen's other western German factories are only possible from December, labour contracts at Osnabrueck are governed differently, making such action possible now.

At around 0930 CET (0830 GMT), workers will start the journey from the plant to the local headquarters of IG Metall, where they will join staff from other local businesses by 1030 CET, the union said.

IG Metall is demanding 7% pay rises compared with an offer from employers' associations of a 3.6% increase over 27 months. Companies say the demands are unrealistic.

Volkswagen's plant in Osnabrueck, which employs around 2,300 staff, manufactures Porsche's Cayman and Boxster models as well as Volkswagen's T-Roc Cabriolet.

But Porsche has announced plans to build the next generations of the Cayman and Boxster at its Stuttgart-Zuffenhausen plant, and Volkswagen will stop production of the T-Roc Cabriolet next year, creating a potential production issue for Osnabrueck.

Last week, Volkswagen works council head Daniela Cavallo said that Porsche management had informed the Osnabrueck plant that it would end their existing business relationship.