Sales at supermarkets in the Centra chain grew 22.5 per cent last year to €652.6 million (£514 million), the group said yesterday.

There are 317 stores in the Republic and when sales at 32 new stores were excluded from the performance last year, sales rose by 16 per cent. The increase followed a 25 per cent rise in sales in 2000.

The group attributed the increase to greater reliance on convenience stores by working couples. Both partners in about 45 per cent of households worked, aid.

Centra's sales director, Mr Michael Smith, said the net profit margin at the stores was 6-7 per cent before finance costs, suggesting an overall net profit of €39.2-€45.7 million in the group last year.

The stores are owned by independent retailers who trade under the Centra brand, which is owned by the Musgrave SuperValu group. Musgrave SuperValu centralises the purchase of stock for the group and provides marketing, management information, technology and store development services for retailers.

The group claims 7 per cent of the overall supermarket business in the Republic, which is worth about €9 billion annually.

It said the average weekly turnover at Centra outlets was €40,000 with some larger provincial stores reporting weekly sales of 120,000.

Store owners spent €60 million on technology and capital development last year and a further €80 million would be invested this year, the group said in a statement.

About 6,000 people are employed by group outlets and a further 1,600 jobs were sustained by the business in Musgrave SuperValu in distribution and retail support services, the group said.