The fortune of the London-based head of ArcelorMittal, the world's largest steel maker, fell by around 22 percent to Â£17.5 billion in the past 12 months, according to an annual rich list compiled by The Sunday Times newspaper.
The drop in his wealth was caused by a fall in the share price of ArcelorMittal.
Mittal's fortunes were markedly different from the rest of Britain's wealthiest, with the 1,000 richest people seeing their wealth continue to bounce back from the recession and increase by 18 percent to Â£395.8 billion.
The number of billionaires in Britain now stands at 73 -- up from 53 last year and almost matching the record of 75 set in the list of 2008 before the financial crisis.
Forty of the billionaires are British-born.
Despite the drop in the wealth of Mittal, chief executive and chairman of ArcelorMittal, he hung on to his place at the top of the list, a position he has enjoyed for the past few years.
In second place is another steel magnate, Russian busine