Chairman and Chief Executive Officer Lakshmi Mittal presents Year 2009 results of Arcelor Mittal steel group during a news conference in Luxembourg February 10, 2010. REUTERS/Thierry Roge

LONDON (Reuters) - British-based steel magnate Lakshmi Mittal topped the list of Britain’s richest people once again as the wealthiest in the country saw their fortunes soar in the last year, the annual Sunday Times Rich List survey said.

The collective wealth of Britain’s 1,000 most affluent people rose by 30 percent, boosted by the improved economic conditions over the last 12 months, the survey said.

Last year, Britain’s wealthiest people saw their fortunes hit by the economic downturn, losing a total of 155 billion pounds with the overall number of billionaires falling to 43 from 75.

This year that number rose to 53, with the overall worth of those on the list seen at 333.5 billion pounds, a rise of more than 77 billion and the largest in the poll’s 22-year history.

Metals magnate Mittal, CEO of ArcelorMittal stayed at the top of the list with his personal fortune more than doubling to 22.45 billion from 10.8 billion.

Russian Roman Abramovich, the Chelsea football club owner who has steel and other investment interests, remained second with a fortune of 7.4 billion pounds.

The richest British-born billionaire, the Duke of Westminster, remained third on the list, with his largely property-based portfolio up four percent to 6.75 billion pounds.

Indian-born Anil Agarwal, chairman of mining group Vedanta Resources Plc was the highest climber on the list, moving to 10th from 60th with his fortune rising almost six-fold to 4.1 billion pounds.

The annual list is based on identifiable wealth, including land, property and other items such as art, racehorses or significant shares in publicly quoted companies, but does not include bank accounts..