General Motors Corp. (NYSE: GM) is trading down sharply after disclosing huge charges last night and after posting a net loss from operation that appears much wider than estimates.

Unfortunately, core operations too were still at a loss. Excluding special items, GM had a 2007 third-quarter adjusted net loss of $1.6 billion, or $2.80 per diluted share, compared to net income of $497 million, or $0.88 per diluted share, in the year-ago quarter. The auto giant posted $43.1 billion in quarterly revenues. If you trust the estimates, First Call estimates called for a loss of $0.11 per share on $40.28 billion in revenues.

GM noted that ongoing challenges in the U.S. mortgage market are impacting GM income from GMAC. The company is recording a $39 billion allowance on deferred tax assets and the net loss for the quarter after write-downs and charges is actually larger than the entire stock price, although the company is also claiming that its liquidity position improved to $30 billion. GM also noted that it reached a record high in global sales, but in light of the wide losses, that seems to be a small comfort now.

Shares are down 8% pre-market at $33.25; the 52-week range is $28.49 to $43.20. You'd have to be named Dr. Pangloss to find any great news here this morning. Shares of Ford Motor Co. (NYSE: F) are also trading down ahead of its earnings report tomorrow, although its shares are "only" down by 2%.

Property prices in Michigan must still be getting cheaper.