Mr Bloomberg’s Economic Development Corporation, which is paying $600,000 (£317,000) for the project, may take a range of measures after the two-month investigation by McKinsey, the management consultancy. The measures could include putting together a committee of heavyweight Wall Street bankers to fight New York’s corner and lobbying to change some of America’s financial regulations, a corporation spokesman said.

The corporation is particularly worried by the recent shift in large international flotations to London as the costly, time-consuming Sarbanes-Oxley rules deter non-US companies from listing in America.

London has a 26.4 per cent share of the global IPOs in which $1 billion or more was raised this year. New York has only 6.5 per cent. In 2001, the year before the Sarbanes- Oxley Act was passed, London had 8.7 per cent to New York’s 59.1 per cent, according to Thomson Financial. The regulations were introduced gradually from 2004 in a move to combat the kind of multibillion-dollar frauds exposed at companies such as Enron and WorldCom.

Many non-US chief executives have balked at the rules, which require them to take full responsibility for their accounts and can take thousands of hours and cost tens of millions of pounds to comply with.

Pete Peterson, of Blackstone Group, the New York-based private equity firm that manages the world’s biggest buyout fund, said: “Sarbanes-Oxley has had some unfortunate and unintended effects. For one thing, foreign companies are far less likely to do their underwritings in the US.”

Josh Lerner, a finance professor at Harvard Business School, cites another reason that New York increasingly is losing out to London. He said: “There have been numerous class-action lawsuits over the years, often resulting in multi-million-dollar out-of-court settlements — whether the company is guilty or not. Managements like to avoid these kind of headaches.”

The recent arrests in America of top British gaming company executives might be a further deterrent, he said.

How America is losing out?

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