The UK's Cooperative Group has posted a 41% rise in operating profit to £327.3m (US$579.7m), driven by a strong performance from its food retail unit.

For the year to 10 January, the Cooperative Group reported a 9.3% rise in income to £7.4bn. Operating profit from trading activities rose 66% to £135.5m. Food retail profits rose 63% to £113.4m.

The group said that during the year it had made continued investment in its convenience store portfolio, with £35.4m of capital expenditure on the refurbishment of 218 stores. It also acquired Balfours convenience and newsagents chain for £31m.

Also during the year, the Co-op switched all of its own brand coffee to Fairtrade.