General Motors underlined its dire financial condition on Thursday as it reported an unexpectedly heavy cash drain in the final three months of 2008 and warned that Deloitte, its auditor, might cast doubt on its standing as a going concern.

The Detroit carmaker, dependent on government aid for survival, reported a fourth-quarter loss of $9.6bn, bringing the 2008 loss to $30.9bn. GM has racked up losses totalling $86.6bn during the past four years.

Adding to its woes, GM disclosed that its pension fund, one of the biggest in the US, has swung over the past year from a $20bn surplus to a $12.4bn deficit.

Kimberly Rodriguez, a restructuring specialist at Grant Thornton, described the going-concern tag as “a stamp on a situation that we all already recognise. The key is how people react. It does provide a vehicle for someone to get out of a lending situation or a commercial agreement.”

Ms Rodriguez said the doubt over GM’s status underlined the need for speedy decisions – one way or the other – on future government aid, not only for GM but also its parts suppliers.

GM has received $13.4bn in emergency loans from the US government, and last week applied for another $16.6bn.

In addition, its foreign subsidiaries have asked for aid from governments in Canada, Germany, the UK, Sweden, Thailand and South Korea.

Rick Wagoner, chief executive, on Thursday met the US government’s auto industry taskforce, which has taken charge of the company’s restructuring. It is due to decide by March 31 on future funding for GM and its smaller, but equally troubled, Detroit rival Chrysler.

GM burned through $19bn in cash last year, and has budgeted for a $14bn drain in 2009.

Ray Young, chief financial officer, ascribed the unexpectedly high fourth-quarter outflow of $5.2bn from automotive operations to the sudden downturn in many hitherto buoyant overseas markets.

Output at GM’s European plants was 53 per cent lower in the fourth quarter than a year earlier. All four regional units reported quarterly losses.

JD Power, a consultancy, on Thursday underlined the challenges facing GM and the rest of the north American car industry with an estimate that US light-vehicle sales would drop to a new annualised low of 9.1m units in February, from 9.6m in January and 15.4m in February 2008.