Sir Stuart Rose, chief executive of Marks and Spencer, is to sell his £100,000 stake in Martha Lane Fox’s karaoke business in a bid to defuse the row over boardroom standards at Britain’s largest clothing retailer.

Institutional investors are concerned that Ms Lane Fox, an independent director at M&S, might be compromised by the investment.

The independence of the non-executive directors is highly sensitive because of Marks and Spencers’s plan to elevate Sir Stuart to the additional role of chairman.

Sir Stuart said today that the disposal was not really necessary. “She is a very independent-minded woman. She doesn’t suffer fools.”

He added: “She’s not the sort of character who would be swayed by a £100,000 investment in her business.”

“But I have in fact unwound my investment in Lucky Voice [the karaoke business]. Perhaps I should have called it Unlucky Voice,” he quipped.

Sir Stuart disclosed the decision to sell the stake at an Investor Relations Society conference this morning. Afterwards he told The Times, “I didn’t want to look arsey and so intransigent that I wasn’t listening to what people were saying. You have to look whiter than white.”

The Association of British Insurers (ABI) raised concerns last week over the chief executive’s dominance in the boardroom after it emerged that Sir Stuart had invested in Ms Lane Fox’s business venture, which has bars in London and Manchester.

Though there is no suggestion of impropriety on the part of either executive, the ABI led other leading shareholders in questioning whether the move could allow Ms Lane Fox to remain an independent voice in the boardroom.

Up until today, Sir Stuart said that his investment was a private matter.

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