Asda has emerged as the retailer with the fastest-growing portfolio of large stores according to the latest UK grocery market data from IGD and William Reed Business Media, publisher of The Grocer.

Asda has opened 18 new supermarkets, superstores and hypermarkets in the past year - more large stores than any other retailer - representing a 5.7% rise to 334.

The estate data, which excludes forecourt numbers, shows Tesco has grown store numbers 6.6%, largely driven by a big push in c- stores, where Asda doesn't operate. Tesco opened 122 c-stores, lifting numbers 10% to 1,341. Total store numbers rose to 2,108.

Tesco has 7% fewer supermarkets but 7.9% more hypermarkets, suggesting it is forging ahead with converting its smaller supermarkets to Tesco Extras.

This reflects a wider trend towards very large stores, with hypermarket numbers up 4.5% among all retailers to 739. Meanwhile superstore and supermarket numbers are down 0.7% and 5% respectively.

In convenience, Tesco was second only to The Co-operative Group in growth, with a 36.8% rise in c-stores to 1,665, driven by its merger last July with United Co-ops. Its supermarket portfolio is up 24% to 552.

The data includes specialists and shows farm shops spreading faster than any other type of shop - supermarkets and hypermarkets included - rising 15% to 1,796. Health food shops and fishmongers are also in healthy growth with independent fishmongers up 7% to 1,025 and health food shop numbers up 6% to 959.

Numbers of traditional CTNs, butchers, bakers and greengrocers continue to decline. CTN numbers have fallen 6.8% over the past year to 4,459. Butchers are also suffering, down 7.1% to 7,075. But specialist confectionery shops were up as Thorntons rolled out its franchise operation, with stores rising 8.1% to 761.

Bob Farrand, chairman of the Guild of Fine Food, said greengrocers and butchers were facing increased competition not from multiples but new farm shops. "Farm shops sourcing locally are taking business away from them," he said. The UK grocery market was worth £134.8bn in the year to May 2008, up 4.1% year-on-year.

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