Doosan Infracore Co., South Korea's leading construction equipment maker, said Tuesday that it has raised US$400 million by selling shares to overseas investors to help improve its financial status. The company said it issued the so-called global depositary receipts (GDR), or certificates of stock ownership, to foreign investors at $10.31, or 10,857 won, per share. The GDRs represent some 38.79 million common stocks and will be listed on the Singapore Exchange on Dec. 20, it said.