The transaction values Asda at 7.3 billion (USD 10 billion, 8.3 billion euros). Walmart will own 42 per cent of the combined business and also receive 2.97 billion in cash.
However, it still remains subject to approval from Britain's Competition and Markets Authority (CMA) regulator, amid concerns over the impact on consumer choice and jobs.
The combined business would have total revenues of ?51 billion and boast a network of 2,800 Sainsbury's, Asda and Argos stores.
No store closures are planned and both brand names will continue to operate side by side.
"The retail sector is going through significant and rapid change, as customer shopping habits continue to evolve," Sainsbury's added.
"This has led to increased competition across grocery, general merchandise and clothing, as customers seek ever greater value, choice and convenience.
"Bringing Sainsbury's and Asda together will result in a more competitive and more resilient business that will be better able to invest in price, quality, range and the technology to create more flexible ways for customers to shop." Sainsbury's previously bought catalogue retailer Argos in 2016 for 1.4 billion.
In Britain's fast-changing retail landscape, Tesco meanwhile purchased wholesaler Booker for 3.7 billion earlier this year.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)