General Motors ( GM) may have finally closed the book on its annual report for 2005, but the world's largest automaker remains in a tussle with organized labor, and its standing with investors is still on shaky ground. The contents of the 10-K filing late Tuesday did little to patch up GM's credibility issues. Aside from the dismal sales and profit figures it had already reported for last year, GM revealed further accounting errors at its residential mortgage division. It also reported increased scrutiny of its financials from federal regulators and cast a veil of uncertainty over its ongoing attempts to sell a majority stake in GMAC, its finance subsidiary. Amid all these problems, GM finds itself at a crossroads with respect to the bankruptcy of its former subsidiary Delphi ( DPHIQ). With a Friday deadline looming, the automaker needs Delphi to reach an agreement with the United Auto Workers union to lower wages paid to its hourly employees. If the sides don't reach an accord, GM faces the prospect of a labor strike at it largest auto-parts supplier -- an event that could result in calamity for the company and the broader financial markets. The three-way negotiations between GM, Delphi and the UAW appeared to be showing progress last week when the companies announced a plan to offer buyout packages to thousands of workers in return for early retirement. But on the thornier issue of wage cuts for Delphi's hourly workers, the company's latest proposal on the table has been so far rejected by the union. "While we still believe that GM, Delphi and the UAW will eventually come to terms and a strike will be averted, we believe tensions will intensify in the near term," said Deutsche Bank analyst Rod Lache in a research note. According to several media reports, Delphi's proposal included cutting hourly wages at its surviving plants to $22 from about $27 this summer, followed by a further decrease to $16.50 to be phased in next fall. In addition, the plan reportedly required workers to pay higher health care premiums and included $50,000 in incentive payments to workers to sweeten the deal.