Kingfisher plans to increase the number of Warehouse branded stores from 30 to 125. The group's original plans called for only 70 stores by the end of 2003.
Sir Geoffrey Mulcahy, Kingfisher's chief executive, said the potential rewards justified speeding up the roll-out of new outlets. The group intends to finance the programme out of its own resources.
"We are confident that more than doubling the planned rate of Warehouse openings will help to ensure that B&Q maintains its record of growth and consistently outperforming the market and competitors," Sir Geoffrey said.
Warehouse estimates that 10,000 of the new employees will be full-time staff and 10,000 will be part time. That figure allows for areas where the opening of a new Warehouse outlet requires the closure of an existing B&Q Supercentre.
The first Warehouse store opened in 1994. The stores' main advantage is their size: at between 100,000 and 150,000 square feet each, they dwarf existing DIY sheds, the biggest of which are about 40,000 sq ft. Each Warehouse store sells 40,000 product lines.
Richard Perks, of retail consultancy Verdict Research, said the deal was a good move for B&Q, but that it would put pressure on the other smaller DIY chains. "These Warehouse stores work. People like them. Kingfisher has refined and significantly improved the format," Mr Perks said.
B&Q leads the DIY market with nearly 20 per cent of the pounds 9bn business sector. It's share has risen from 15 per cent in the past three years. Sainsbury's Homebase is number two.
Kingfisher, which also operates Woolworth, Comet and Superdrug stores, recently announced a planned link between B&Q and the French improvements group Castorama to create Europe's biggest DIY group. Kingfisher will hold 54.6 per cent of the joint venture and 50 per cent of voting rights.