General Motors Corp. posted a $9.6 billion fourth-quarter loss and said it burned through $6.2 billion of cash in the last three months of 2008 as it fought the worst US auto sales climate since 1982 and sought government loans to keep the century-old company running. The biggest US automaker said Thursday it lost $30.9 billion for the full year and expects an opinion from its auditors as to whether the company remains a “growing concern” when its annual report is issued in March. That means the auditors will determine whether there is substantial doubt about the automaker's ability to continue operations. Thousands of Opel workers from around Germany took part in a mass rally on Thursday at the company's headquarters, demanding parent General Motors scrap plans for plant closures in Europe. Carrying banners reading “Free Opel” and “Opel cannot be allowed to die”, the workers came to Opel headquarters west of Frankfurt from around Germany. Chief Financial Officer Ray Young said the determination will depend a lot on whether GM gets further government loans and whether it can accomplish its restructuring goals. The company has received $13.4 billion in federal loans since Dec. 31 and says it needs up to $30 billion to stay out of bankruptcy. Top GM executives were in Washington, DC, Thursday to meet with the Obama administration's auto task force to talk about restructuring and additional loans. “2008 was an extremely difficult year for the US and global auto markets, especially the second half,” Chairman and CEO Rick Wagoner said in a statement. “These conditions created a very challenging environment for GM and other automakers and led us to take further aggressive and difficult measures to restructure our business.” GM reported a net loss of $15.71 per share for the fourth quarter, compared with a loss of $722 million, or $1.28 per share in the year-ago period. Quarterly revenue fell 39 percent to $30.8 billion from $46.8 billion, as credit availability froze across the globe, and a lack of consumer confidence and fears of job losses kept people from buying vehicles. Excluding special items, GM's fourth-quarter adjusted loss was $5.9 billion, or $9.65 per share. That was worse than Wall Street expected. Analysts surveyed by Thomson Reuters predicted a quarterly loss of $7.40 per share on sales of $35.1 billion. For the full year, the loss was $53.32 per share, the second-worst annual result in the company's history. The worst loss occurred in 2007, when GM lost $38.7 billion, or $68.45 per share, in 2007, due largely to charges for unused tax credits. GM shares fell 22 cents, or 8.6 percent, to $2.33 in premarket activity.