Supermarket group Morrisons has reported a rise in half-year profits as record customer numbers helped to drive improved sales.Net profit for the six months to the end of July was £442m, up 7.3% on the £412m made a year earlier. Turnover rose by a similar percentage to £8.7bn.The company said on average 11.5 million customers visited its stores during the period - a record number.It said it was confident of further progress in the rest of the year.This is despite what the group called the "challenging trading environment", which it sees as continuing "for some time to come".Excluding fuel, like-for-like sales in the first half half of the year, which strip out the impact of sales from new stores, rose by 2.2%.These were helped by the group's "Price Crunch" promotional campaign.While many High Street retailers have struggled with difficult trading conditions in the current economic climate, food retailers have fared relatively well.Figures released by the British Retail Consortium earlier this week suggested that food and drink was the only category in which UK retail sales rose in August from the previous month.In 2010, Morrisons made a pre-tax profit of £874m. From/ BBC