ThyssenKrupp AG has announced that it plans to close a Detroit plant that has built auto parts for 81 years, citing a lack of orders.The plant, which has about 350 employees, will be shut by the end of 2006, ThyssenKrupp's United States announced in a statement. Production will move to a factory in Shelbyville, Ky. The 2-million-square-foot factory builds parts mainly for Ford's Expedition and Lincoln Navigator large sport-utility vehicles. Combined United States sales for those vehicles fell 23 percent this year through April. According to a spokesman for ThyssenKrupp, most of the remaining employees at the plant are United Automobile Workers (U.A.W.) union members who are nearing retirement. The company is negotiating with the U.A.W. on the terms for phasing out the factory.