Activist investor Knight Vinke has built up a 3% stake in Anglo-French electricals retailer Kesa, owner of the Darty and Comet chains.

The share buying came after the Anglo-French retailer’s results last week and as some investors question whether Kesa’s strategic review is fast enough and deep enough to cope with a rapidly changing market.

Kesa’s arch-rival DSGi has been successfully overhauled and US giant Best Buy has begun opening its big-box stores in this country.

Knight Vinke has previously pressured for change at companies such as HSBC and Royal Dutch Shell and may view Kesa as being undervalued.