Hanwha Chemical Co., a unit of South Korea's Hanwha Group, said Thursday it will raise US$340 million by selling its shares to overseas investors. The global depository receipts (GDRs), or certificates of stock ownership, were priced at $15.7 each, the company said. The GDRs represent some 216.56 million common stocks and will be listed on the Singapore Exchange on May 9, it said