General Motors Corp. says there is “substantial doubt” about the company’s viability and that bankruptcy is possible unless it can implement a broad restructuring plan, according to a regulatory filing today. The comments came in GM’s delayed annual report filed with the Securities and Exchange Commission. Auditor Deloitte & Touche cited GM’s continuing losses from operations, its negative net worth and an inability to generate the cash needed to run its business.

“If we fail to do so for any reason, we would not be able to continue as a going concern and could potentially be forced to seek relief through a filing under the U.S. Bankruptcy Code,” GM said. Stocks trimmed losses on Thursday after data showed new orders received by U.S. factories fell for a sixth straight month in January but the drop was less than expected. Even so, worries about General Motors’ <GM.N> viability and declines in financial and energy shares kept stocks in the red the day after a rally snapped a five-day losing streak.