General Motors is to take a $39bn (£19bn) non-cash charge against third-quarter earnings as a result of writedowns in future tax benefits.

The US carmaker made the announcement on the eve of releasing third-quarter earnings today. Analysts had expected GM to report a sizeable loss mainly because of losses reported by ResCap, the real-estate arm of GMAC, the financial services group in which GM has a 49 per cent stake.