Lakshmi Mittal, rated by Forbes as the world's fifth richest man, worth $23.5 billion, ($46 billion) has pledged to invest $200 million in the flagship hedge fund of London-listed RAB Capital and has raised his stake in the company from 5.4 to 6.2 per cent through a new share issue. The new Mittal money is locked in, with an agreement from the family not to withdraw within three years and to give a year's notice for withdrawals in the following two years. This will give RAB a further opportunity to invest in illiquid investments and private equity deals in the search for returns. RAB Capital has $5 billion in assets under management, $1.3 billion of which is in the Special Situations fund which has returned 30 per cent in the first 11 months of the year.