Marks & Spencer is to breathe new life into 100 of its stores with a £40m refurbishment programme this year, the retailer said yesterday.

The work, which should be completed before the Christmas shopping season, is expected to create ''a brighter and more modern environment''.

It is the second stage of a three-year improvement programme unveiled last March by chairman and chief executive Luc Vandevelde.

Yesterday, speculation was growing that Mr Vandevelde could soon announce he is to give up the dual role and become non-executive chairman.

Roger Holmes, head of the company's UK retailing business, is tipped to take over the chief executive's role.

The change is expected to be announced with M&S's full-year figures on May 21, although a spokeswoman yesterday dismissed the reports as ''speculation''.

The decision still needs to be approved by the M&S board and much could hinge on continued signs of recovery being shown in the group's fourth-quarter trading figures, due next Tuesday.

Mr Vandevelde, a Belgian food retailer, joined the group in early 2000 and has recently seen a sales revival after a difficult start to his tenure.

Trading over the Christmas period was described as ''strong'', with like-for-like sales in the seven weeks to January 12 ahead by more than eight per cent.

The Per Una women's fashion range has helped improve the company's trading performance, while the first 100 refurbished stores have been introduced at a cost of £80m.

Work on the latest store renewals is scheduled to begin this month and will cover another 17 per cent of the group's existing selling space.

About a third of the outlets will gain Cafe Revive coffee shops while 40 will include Classic shops, featuring a range of clothes for older customers.

The final stage of the renewal programme for M&S's 312 UK stores will be completed next year.

Renewal programme manager Simeon Piasecki said: ''We aim to create a relaxed and refreshing shopping environment for our customers to shop within.''

M&S will begin its refurbishment programme at stores in East Kilbride, Harrow, Barrow-in-Furness and Marble Arch, London. It is expected that work at each store will take six to eight weeks to complete.