GM said it was following accounting guidelines with respect to deferred tax assets in three countries.
Excluding the charge, GM still posted a net loss of $1.6bn (£900m) for July to September, compared with a $147m (£70m) loss for the same period a year earlier.
While GM reported a quarterly dive in profits, Toyota posted its second-highest quarterly profit ever of £2.37bn, and raised its full-year profit forecast to £7.1bn.
Fritz Henderson, GM’s chief financial officer, said the company’s goal was to move into "a more sustainable profit position" but would not speculate on how long that would take.
"We need to significantly restructure the business to staunch those losses and then frankly reassess where we go from here," he said of GMAC's future.
"But at this point I have to say that the outlook is uncertain."
Operating results were hurt by subprime mortgage difficulties at GMAC, in which GM holds a 49% stake. GMAC's Res Cap mortgage division lost $2.3bn (£1.1bn) in the quarter, causing a net loss of nearly $1.6bn (£800m). GM's share of the loss was $757m (£360m).
Henderson wouldn't predict when GMAC would be profitable, but he said GM is not planning to sell or reduce its GMAC stake.