Porsche joined other German carmakers Saturday in announcing a temporary halt to production because of dwindling sales triggered by the global economic crisis, DPA reported. A spokesman for the sports carmaker in Stuttgart said the company was extending the Christmas holiday period for workers by three days. He said the company's main plant at Zuffenhausen would remained closed from December 22 until January 9, 2009. A spokesman confirmed media reports that if sales do not pick up, Porsche might transfer some of the production of its Boxster model from its Finnish partner Valmet to Germany. On Monday, Daimler AG announced plans to shut down work for about four weeks over Christmas at key plants, including one producing its flagship luxury Mercedes-Benz cars. The move followed similar announcements by General Motors, maker of Opel cars, and luxury carmaker BMW. The deepening economic gloom resulted in European car sales slumping to their lowest level in a decade in September, according to the Brussels-based European Automobile Manufacturers Association. Despite the downturn, Volkswagen, Europe's biggest automaker, looks set to invest 3.2 billion euros (4.1 billion dollars) in new components plants in Germany, China and North America. The trade magazine Auto Motor und Sport said the VW board was expected to approve the plan at a meeting on November 14. The plant in China would produce transmission systems, while one at Kassel in Germany would make electric motors for hybrid cars, the report said Saturday. dpa ms ncs