American International Group on Monday revealed the depth of its financial plight with a $61.7bn quarterly loss – the largest in US corporate history – and pointed to the next trouble spot for the financial sector by reporting large writedowns in commercial real estate.

The fourth-quarter results came as AIG confirmed it would give the US government a large stake in its two largest divisions as part of a $30bn-plus rescue package that could lead to a break-up of the 90-year-old insurer.