Britain's Sainsbury's and Asda agree merger

LONDON, April 30 (Reuters) - Sainsbury (Amsterdam: SJ6.AS - news) 's and Asda, the UK arm of Walmart, confirmed on Monday they are to merge to create Britain's biggest supermarket group by market share, surpassing current leader Tesco (Frankfurt: 852647 - news) .

The combination will result in Walmart, the world's biggest retailer, holding 42 percent of the equity of the combined business and receiving 2.975 billion pounds ($4.1 billion), valuing Asda at about 7.3 billion pounds.

Joining together the UK's second and third-biggest supermarket chains will reduce costs and increase buying power but could face major regulatory hurdles. ($1 = 0.7255 pounds) (Reporting by James Davey; editing by Sarah Young)