SUPERMARKET chain J Sainsbury has shown its recovery is firmly on track by posting a surge in sales.

The group, which has been attempting to reassert itself in the face of stiff competition, said like-for-like sales for the 12 weeks to March 30 were up 6.8 per cent, excluding petrol.

Sales were boosted by the chain's advertising campaign starring TV chef Jamie Oliver and strong demand for the upmarket Taste the Difference range, while Easter contributed 1.5 per cent.

The final surge helped underlying sales growth for the year as a whole, again excluding petrol, reach 6.3 per cent.

Chief executive Sir Peter Davis said the group had seen five consecutive quarters of strong sales growth.

He said: "These numbers demonstrate a sustained step change in our UK supermarkets' sales performance.

"This is clear evidence that our strategy of upgrading our store portfolio, combined with offering outstanding quality and great service at competitive prices, is being well received by our customers."

Sir Peter said demand had been high for fresh food, CDs and DVDs as well as the Taste the Difference range, while the Jamie Oliver adverts had "undoubtedly been very effective, in all parts of the country".

Also drawing in customers was a programme to improve its stores. Sainsbury's said it had refitted 117 shops during the year to March 30.

Sir Peter said: "What we have seen for six months now is market share gains.

"That's the first time we have seen that in five-and-a-half years.

"It is not at the same rate as Tesco and Asda, but we have joined the people making market share gains."

The London group said its market share in the past 12 weeks was 11.7 per cent, 0.1 per cent up on the previous year.

Sainsbury's also operates in the US through Massachusetts-based chain Shaw's, which has 185 stores across New England.