Manchester United chief executive Richard Arnold is stepping down from his role, the club announced on Wednesday, as British billionaire Jim Ratcliffe edges closer to becoming a minority stakeholder.

Arnold, 52, has been at the club since 2007 and replaced Ed Woodward as United's top executive in February last year.

"Richard Arnold has decided to step down as chief executive of Manchester United after 16 years with the club," United said in a statement.

"Patrick Stewart will take over as interim CEO, in addition to his existing role as general counsel, with Richard continuing to provide transitional support until the end of December. A search process will be carried out for a new permanent CEO."

Arnold said it had been an "incredible privilege" to work at United.

"Through highs and lows, the constant has been the dedication of our employees and fans," he said.

"I would like to thank all of them for their loyalty and commitment, and wish everyone associated with the club the very best for the future."

Ratcliffe's Ineos Group is expected to pay about £1.25 billion (US$1.56 billion) for a minority stake in the Old Trafford club, while also acquiring significant control over footballing operations.

The BBC said the deal was expected to be ratified during the current international break, possibly as early as this week.

Arnold oversaw the appointment of current manager Erik ten Hag in 2022, who last season ended the club's six-year trophy drought.

But United have had a disappointing start to the 2023/24 campaign, losing nine of their first 18 games in all competitions.

The Glazer family announced in November 2022 that they were considering "strategic alternatives" to help the club grow, which included consideration of a sale.

Qatari banker Sheikh Jassim bin Hamad Al Thani and Ratcliffe made offers in the region of £5 billion for a complete takeover, but that fell short of the Glazer family's valuation.

Sheikh Jassim withdrew from the process last month, while Ratcliffe continued to pursue a minority shareholding.

Ratcliffe, 71, who tried to buy Chelsea last year, grew up in the Manchester region and describes himself as a lifelong fan of United.

The deal is likely to lead to a major shake-up of United's football operations. Dave Brailsford, the former performance director of British Cycling, is expected to have significant influence in his role as Ineos's director of sport. (AFP)