Toshiba files results unapproved by auditor; warns of 'going concern' risk

By Makiko Yamazaki and Taiga UranakaTOKYO (Reuters) - Toshiba Corp filed twice-delayed business results on Tuesday without an endorsement from its auditor and warned its very survival was in doubt, deepening a prolonged crisis at the Japanese conglomerate."There are material events and conditions that raise substantial doubt about the company's ability to continue as a going concern," Toshiba said in announcing bigger than previously estimated losses for the nine months through December.The fili