French insurer Axa has revealed its estimated 2002 US loss was almost double its original forecast, at 2.9 billion euros (£1.9 billion).
An analyst told Reuters that said the revision marked a stricter interpretation of US accounting laws.
Commerzbank London analyst Andrew Goodwin said: "One of the problems is that there is an element of subjectivity in the treatment of impairment losses. In my view, it's not that significant an item... It's just stricter rules."
The insurer had estimated in its results on 27 February that it would show a EUE 1.6 billion euros (£1.1bn) under the US Generally Accepted Accounting Principals (GAAP).
The new information was not yet audited and consequently subject to change, Axa said.
