Berkshire Hathaway, the investment company that has interests in UK insurers Faraday and NIG, has reported its highest ever annual profit of $4.2bn (£2.6bn).
The holding company, run by billionaire investor Warren Buffett, said the improved results were supported by rising insurance rates.
The results compared with a profit of $795m (£496.2m) for 2001, when Berkshire put aside more than $2bn (£1.2bn) to cover claims arising from the 11 September attacks.
Buffett, also revealed that measures designed to improve the quality of management at US companies might not prove worthwhile.
He said: "It's time for CEOs to walk the walk."
He added that bosses would probably agree to "meaningless proposals of reform", but many would fight "a hard look at their own pay and perks".
US companies are facing up to tighter rules on boardroom behaviour, after the passage of the Sarbanes-Oxley Act last autumn, spurred by a string of corporate scandals including Enron's collapse.
