The billionaire owners of a petrol station operator and private equity group tdr capital have bought asda from walmart, ending the us retailers 20-year foray into britain that fell short of initial expectations.

The transaction values the uk grocer at 6.8bn, slightly more than the 6.7bn walmart paid for asda in 1999.

Brothers mohsin and zuber issa and tdr which jointly own british petrol station operator eg will hold equal stakes in the uks third-largest supermarket, with walmart retaining a minority shareholding.

The exact details of the size of the buyers stakes and how much they paid for them were not disclosed.

Asdas existing management team, led by chief executive roger burnley, will remain in place.

Judith mckenna, president and chief executive of walmart international and a former asda employee, said the group believed the transaction creates the right ownership structure for asda.

Im delighted that walmart will retain a significant financial stake, a board seat, and will continue as a strategic partner. asda has been a powerhouse of innovation for the rest of the walmart world, and we look forward to continuing to learn from them in the future, she added.

The issa brothers, who started eg from a single forecourt in greater manchester,said they were very proud to be investing in asda, describing it as an iconic british business that we have admired for many years.

The brothers and tdr said asdas headquarters would remain in leeds and that its basic strategy of everyday low prices would continue. many observers expect the new owners to push into convenience retail, given the brothers background in forecourt retailing.

Blackburn-based eg, previously called euro garages, has convenience stores including spar and carrefour on its forecourts but the brothers have no experience of running large-format supermarkets.

The entry of walmart, the world's biggest retailer, had promised to shake up the uk grocery sector, which was known at the time of the asda deal for high prices and unexceptional service. but the us company ultimately failed to dominate in britain, in part because asda faced mounting competition over the years from hard discounters aldi and lidl.

Column chart of underlying pre-tax profit (m) showing profits at asda

Walmart had been seeking an exit from asda for some time to focus on the us and faster-growing overseas markets. its uk business has faded in comparison with overseas ventures in china and india. asda generated 23bn in sales in its 2018 financial year, making it a small part of the us retailer, which had total revenues of $500bn in 2018.

An attempt to sell a majority stake to rival j sainsbury was blocked by the uks competition and markets authority last year. the cma may scrutinise this deal too, since asda owns more than 300 forecourts and eg has almost 400.

Gary lindsay, a partner at tdr, said: we are proud to be investing alongside mohsin and zuber, who have built eg group into a global convenience retailer and will now bring that experience to bear at asda. we look forward to supporting them, and roger burnley and the management team at asda, to build on the businesss inherent strengths.

Two other us-based private equity firms, apollo and lone star, had also been considering a deal for asda but lone star withdrew last month.