FRANKFURT, Jan 3 (Reuters) - Germany's IG Metall labour union called on staff at Volkswagen's Porsche sports car brand to walk off their shifts for about an hour on Thursday as part of its campaign for higher pay across the engineering industry.
The country's biggest union is demanding a 6 percent wage rise this year for about 3.9 million workers in the metal and engineering sectors, including the German car industry.
It is entitled to stage walkouts after a non-strike period ended on Sunday and many workers usually respond to its calls for action.
The union, which also wants a shorter working week, plans to expand stoppages across Germany from next Monday to step up pressure on employers before the next round of pay negotiations, due on Jan. 11.
Employers have dismissed the pay claim as excessive and have so far offered only a 2 percent raise as well as a 200 euro ($240.50) one-off payment in the first quarter.
Porsche, the second-biggest contributor to Volkswagen (VW) group profit, assembles the 911 and Boxster models at its core factory in Zuffenhausen where the so-called warning strikes have been called.
"The current stance of the employers' lobby is a provocation to workers," Porsche works council chief Uwe Hueck said in an emailed statement.
"The metal and engineering industry has never before made so much profit. That's why there is only one appropriate response: Warning strikes."
A spokesman for the Suedwestmetall employers lobby did not return calls seeking comment.
Several hundred workers at companies including auto components supplier Robert Bosch laid down their tools on Tuesday in support of IG Metall's calls for higher wages. ($1 = 0.8316 euros) (Reporting by Ilona Wissenbach; Writing by Andreas Cremer; Editing by Adrian Croft)