LONDON, United Kingdom — Marks & Spencer Group Plc plans to close around a third of its large UK stores over the next four years, as the retailer belatedly adapts to the rise of e-commerce.

M&S will close more than 100 stores that sell both clothing and food by 2022, the company said in a statement Tuesday. The London-based retailer is aiming to increase the proportion of online clothing sales to one-third, from about 18 percent now.

Slimming down is “vital for the future of M&S,” Sacha Berendji, director of retail, operations and property, said. “Where we have closed stores, we are seeing an encouraging number of customers moving to nearby stores.”

The shares fell as much as 2.9 percent in London, giving back Monday’s gains.

Under Chairman Archie Norman, M&S is taking more drastic action to halt its loss of market share to online rivals and discounters. J Sainsbury Plc’s $10 billion acquisition of Walmart Inc.’s Asda will create the UK’s largest retailer and intensify the pressure on M&S in clothing and food.

Online shopping accounts for 22 percent of non-food retail sales in the UK, according to the British Retail Consortium. That shift is forcing merchants to operate from fewer, higher-quality locations. M&S said its remaining clothing and home stores will be larger and more oriented around technology. Fourteen stores will be closed in M&S’s current financial year and 21 have already been shut.

M&S also said it will open 15 fewer Simply Food outlets, which don’t sell clothing, this year. The retailer had planned to open 200 more food stores from 2017. Its food stores will double up as next-day order collection points for clothing purchases, the retailer said. M&S has more than 1,000 stores, but nearly 700 of them sell food only.

M&S reports full-year results on Wednesday.

By: Sam Chambers, Editor: Eric Pfanner.