Supermarket Sainsbury's has reiterated caution over second half sales growth as it reported an 18.5% rise in profits for the first six months of the year.
The UK's third biggest grocery chain posted underlying profits of £307 million after sales rose 5.7% on a like-for-like basis in the 28 weeks to October 3.
Having previously warned that easing food inflation would slow sales growth, the group confirmed market growth was expected to fall back in a challenging environment.
Shares rose 2% after profits figure bettered the £300 million expected in the City.
The market share data indicated that the retailer's resurgent sales performance in recent months may be coming to an end.
Research from Nielsen suggested Sainsbury's suffered the lowest sales increase among the big four chains in the three months to October 31, with market share growth also easing as Tesco returns to form.
Sainsbury's had emerged as a surprise winner in the recession as it tempted shoppers away from Tesco and more expensive grocers, led by successful advertising campaigns such as Feed your Family for a Fiver.
It is in its fifth year of like-for-like sales growth, with consistent growth above its medium term targets of 3% to 4% in recent quarters.
The 5.7% rise in half-year comparable sales, excluding VAT, compares against 3.9% a year earlier.
But it faces a tough challenge to maintain the sharp rises in sales seen over the past year as food prices ease back and the expected economic recovery arrives.
