Top British retailer beats profit forecasts after major investment

"This buys the company some time to rediscover the magic potion which may tempt younger shoppers into its stores," Richard Hunter, head of equities at Hargreaves Lansdown, said.

"Management appears to be more confident on the general merchandise gross margin opportunity overall. With weak (comparatives) ahead, risk on numbers remains on the upside," Investec analyst Kate Calvert, who has a 'buy' rating on the stock, said.

M&S' first-half underlying pretax profit rose 6.1 percent to 284 million pounds ($438 million), ahead of analysts' average forecast of 270 million pounds, on total sales up 1.4 percent to 5.0 billion pounds.

While UK profits rose 14.6 percent, overall profit growth was held back by a weak international performance, where profit slumped 52 percent, hurt by currency and macroeconomic issues particularly in Russia, Ukraine and Turkey.

In food, M&S is outperforming Britain's grocery industry, benefiting from product innovation and a focus on quality and providing for special occasions.

Second quarter like-for-like sales in food rose 0.2 percent, a 24th straight quarterly increase.

Prior to Wednesday's update analysts were, on average, forecasting M&S' underlying pretax profit for the full 2015-16 year of 703 million pounds, up from 661 million pounds in 2014-15.

Haitong Research analyst Tony Shiret expects consensus to rise by 10-15 million pounds.

Bolland declined to comment on how long he planned to stay as M&S CEO but reiterated he would definitely be around to present full-year results in May.

"I'm enjoying this role tremendously," he said.