The business on...Robert Swannell, Chairman-designate, M&S

Is that old smoothie Stuart Rose off at last?

Sir Stuart to you. But yes, Marks & Spencer will shortly have to cope without him. Having been replaced as chief executive by Marc Bolland earlier this year, Sir Stuart is to give up the chairmanship early in 2011 and Mr Swannell is to replace him.

Will he be as entertaining?

Probably not. While Sir Stuart's acerbic wit is deployed regularly in public, Mr Swannell is renowned as an investment banker to whom the word gentlemanly doesn't quite do justice. Sir Stuart is often seen quaffing champagne in Annabel's, whereas a liking for Bob Dylan is about as racy as the new man gets.

So what does he know about the retail business?

Not as much as his predecessor, but he has been chairman of HMV for the past 18 months, so he's got to know the high street.

But selling CDs to teenagers isn't quite the same as running Britain's favourite shop

Perhaps not, but Mr Swannell knows M&S pretty well – the retailer has him to thank for the fact it escaped the clutches of Sir Philip Green during that vicious takeover battle in 2004. He and Sir Stuart go way back and his friend only joined M&S on the condition that Mr Swannell would be appointed its investment banker. The pair of them then saw off Sir Philip.

He can fight his corner, then?

Well gentlemanly doesn't have to mean soft, you know. In a 33-year City career – he joined Schroders in 1977 and stood down in March as a vice-president of Citigroup, which 10 years ago bought the bank – he is the veteran of a string of boardroom battles. He advised on the Grand Metropolitan deal with Pernod Ricard and more recently on the sales of P&O, Pilkington and Safeway. Just for good measure, he helped Roman Abramovich to buy Chelsea FC.

Goodness, is M&S planning some sort of takeover spree?

Maybe – it has already been linked with a bid for Ocado, the loss-making online grocery business whose value has plummeted since its flotation last month. But the appointment may just signal M&S that is keen to improve relations with the City – Sir Stuart has been fun, but there's no denying he's put a few noses out of joint.