Tesco has extended its lead over rivals in chilled fish after hooking shoppers with salmon deals.

Total value sales of chilled fish at Tesco rose 6.9% to £307.5m in the year to 19 February 2012, according to new data from Kantar Worldpanel.

Tesco’s performance is in stark contrast to the sluggish fish sales seen by its big four rivals. Chilled fish sales at Asda climbed by just 0.1% to £116.2m while Sainsbury’s achieved 0.5% growth to £236.3m. Morrisons actually saw value sales fall by 0.1%, to £167.6m.

Tesco was the only one of the big four to report an increase in chilled fish volume sales, shifting 2.2% more volume than a year ago, while volume sales at Asda, Sainsbury’s and Morrisons were down by 8.9%, 6.4% and 5.8%, respectively.

Tesco fish supplier Seachill claimed the chain’s strong performance was down to improved availability and better deals.

“They’ve got a very strong salmon offer, coupled with availability to meet consumer demand,” said sales and marketing director Simon Smith. “They’ve made the most of the falling salmon price.”

Smith cited Tesco’s first-to-market pre-packed 1kg salmon side - priced at £10 and supplied by Seachill - as an example of an offer that had helped drive growth.

Tesco’s rivals will be keen to close the gap, and some are already revamping their propositions. This week Asda announced it would relaunch its fresh fish counters in 302 stores, offering a wider range and allowing them to pair fish with marinades, sauces, flavoured butters and crumb toppings.

Morrisons announced last week that it had acquired a vacant factory in Grimsby, which it intends to convert into a fish processing site.