A ban on grocery retailers selling or letting land under restrictive covenants would give a major boost to M&S's expansion, according to chief executive Stuart Rose.

Last week, in its provisional grocery inquiry findings, the Competition Commission said it was considering outlawing the practice in order to increase consumer choice.

Speaking as he unveiled the company's interims, Rose said M&S, which wants to increase its selling space by 15%-20% in five years, stood to benefit if that was the outcome of the inquiry.

He added: "I've had conversations with some chief executives where I say: 'Why is it you've got a covenant that says I can only trade either no food, or only 2,000 sq ft? That is crazy.' So we welcome this."

Rose said it was also good news for M&S's growth strategy that the Commission now considered the retailer an effective competitor to the big four. This meant it could now bid for stores or land in areas monopolised by one retailer and where the authorities decided more competition was required.

On Tuesday M&S reported total like-for-like sales up 1.6% and food up 0.5% in the 26 weeks to 29 September.

Total sales rose 6.5% to £4.2bn, with UK sales up 5.9%. Pre-tax profit rose 11.5% to £452m. Like-for-likes had been hit by a store modernisation programme, but this was now 70% complete, said Rose. Food sales at refurbished outlets rose 4.2% on average.

The roll-out of Simply Food stores increased M&S's total food sales by 7.5% in the second quarter. The company opened 62 Simply Foods in the first half, including 47 BP forecourts. A further 60 BP franchises would open next year, as M&S worked towards a target of 200.

Franchise stores netted a higher operating profit than a standard Simply Food store as there was minimal M&S capital employed, said Rose. Abroad, M&S said it planned to add 30%-40% to its space in the Republic of Ireland and open its first wholly owned stores in mainland China.