'I'm worth it' says trader as he is handed record-breaking £156m bonus

Adam Levinson was given the $300million share grant by employer Fortress Investment Group LLC as a sweetener to prevent him leaving for a competitor or starting his own firm.

The 38-year-old chief investment officer joins the private equity and hedge fund giant's five other controlling shareholders, who together hold about £1.6billion of company stock.

24-hour job: Adam Levinson, seen with socialite Brittany O'Neal, is a regular on the New York scene but always in phone contact with work

These executives have not sold any shares since the company went public in 2007 and they own 77 per cent of the business.

Mr Levinson's windfall is nearly four times the size of the $84 million (£44 million) pay package commanded by the highest-paid US chief executive last year, Merrill Lynch's John Thain.

But it is understood that in return for the sum, Mr Levinson must reduce his profit-sharing interests in certain Fortress funds.

Fortress, which has lost two thirds of its peak value in the past 18 months, has refused to comment on the bonus but it has angered some in the financial community.

Citigroup analyst Prashant Bhatia said the share package hurts existing shareholders by increasing the total number of shares by seven per cent.

Today, Mr Levinson defended the award, saying he works 24 hours a day, with more than 12 hours at the office and calls through the night.

He and his wife, who own a loft apartment in Manhattan, are regulars on the New York social scene and have recently had their first child.

Mr Levinson said his job was more likely to wake him than his child.

'Five months into it, the baby sleeps through the night but the calls keep coming,' he said. 'On a good day, it's a couple of calls overnight. On a bad one, it's seven.'

His day starts at 5.10am when he does 20 minutes of Mysore yoga. He arrives at his office at 6.10am for calls with his Asian and London teams. He never takes a lunch break but stops work at 4pm when the US market closes, and then he heads to the gym.

He returns to the office at about 6pm for the opening of the Asian markets.

Mr Levinson, who is originally from Detroit, helps oversee a staff of 170 in six offices around the globe that place bets on a range of investments including US equities and Kazakhstan credit for the firm's $8.8 billion global macro hedge fund.

His current project is evaluating the investment implications of the war between Russia and Georgia.

The size of his reward underlines the massive bonuses still on offer in the opaque world of hedge funds.

London-based GLG Partners recently revealed that one of its best performers is leaving to set up his own fund.

Greg Coffey, a 37-year-old Australian, was prepared to forgo share options potentially worth £160 million because he believed he could make more by striking out on his own.