Compliance with Sarbanes-Oxley has cost Britain's biggest company, BP, $100m a year.

BP chief executive, Lord Browne has told The Daily Telegraph that the oil giant's 'external costs' incurred by complying with Sarbox have topped $100m (£60m) a year.

'Of course, that doesn't count the time we spend on it internally,' he told the paper. 'The fact is that we do it and we do it very efficiently and comprehensively.

'I don't see any easy way back from where we are at the moment. I just don't see it. It's possible that someone some time will have a very, very good idea that maybe it's excessive, maybe it should be rolled back… I do see a bit of moderation in the rate of increase.'

He said that increasing demand for corporate transparency following US scandals such as Enron and WorldCom has been one of the biggest changes on the business landscape in the past 10 years.