Delphi Corp said it will invest US$40.5 million to increase capacity at its factory in Suzhou, Jiangsu province. The US firm has invested nearly US$500 million in 12 factories around China. Delphi supplies four large producers on the mainland including the Volkswagen and General Motors joint ventures. One-fourth of Delphi's China-produced products are exported. Delphi is the world's largest supplier of auto parts.