LONDON (Reuters) - Asda, the British supermarket arm of Walmart
Asda, which agreed in April to be taken over by rival Sainsbury's
The supermarket group said Russo had a new job but did not disclose where it was.
"Alex has been discussing his desire to seek a new challenge for more than a year and we're delighted that he has found the right business opportunity that he has been looking for," said Asda chief executive Roger Burnley.
McWilliam left Asda in 2012 after 15 years in the business to lead finance and consumables for Amazon UK.
In January he started working with Asda again on a consultancy basis.
"We've been looking for a CFO who combines a deep knowledge of UK grocery retail, knowledge of Asda and Walmart relationships, and the skills to support the work we have to do to successfully complete our combination with Sainsbury's," said Burnley.
Sainsbury's takeover is currently being probed by Britain's regulator, the Competition and Markets Authority.
($1 = 0.7585 pounds)
(Reporting by James Davey, Editing by Paul Sandle)