Doubled profits at B&Q helped Kingfisher's first quarter profit jump by over 40%, with the retailer also hopeful on prospects for the rest of the year.Total sales in the three months to end April rose by 9.6% to £2.64bn with like-for-like sales down by 1.7%. Sales rose by 2.4% on a constant currency basis.Profits jumped by 40% to £128m and by 38.5% excluding currency movements.The UK drove the recovery. Sales over the period rose by 2.9%, with retail profit up 89%. B&Q's sales rose by 4.6%, and by 3.2% on a like-for-like basis. B&Q's retail profit doubled, benefiting from higher sales volumes and continuing margin and cost improvementsElsewhere, outdoor seasonal product sales were boosted by more favourable weather in the UK and France and a later Easter compared to last year, though non-seasonal sales continued to decline, Kingfisher said.In France, sales were up 1.7%, and retail profit up by 3.5% benefiting from cost initiatives. The problematic Chinese business continued to struggle. The store portfolio has been rationalised from 62 to 51 since the end of the quarter. As anticipated, sales in China continued to decline sharply in a weak housing market and fell by 24%, while losses jumped to £14m."Whilst there is still work to be done I am confident that B&Q is emerging from its renewal phase in better shape to convert sales volumes into cash profits. I am also encouraged that our French and Eastern European businesses continued to grow sales and profits in slower markets," chief executive Ian Chesire said.