Asda, the British arm of U.S. retailer Wal-Mart , has struck a deal with a leading cookery school, as supermarkets battle to tap a growing trend towards premium foods.

Asda, Britain's second-biggest supermarket group behind Tesco , said on Wednesday it had agreed a long-term strategic partnership with Leiths School of Food and Wine, whose graduates include TV presenter Lorraine Pascale.

Leiths, set up in 1975, by restaurateur Prue Leith and business partner Caroline Waldegrave, will create and develop Asda's Extra Special premium own-brand range of groceries and wines.

Premium foods are becoming a key battleground among retailers as cash-strapped Britons cut back on restaurant meals and look to treat themselves more cheaply at home.

They also offer a way for supermarkets to boost profit margins at a time of intense price competition on staple products like milk and eggs.

Wm Morrison , the country's fourth-biggest grocer, recently launched its M Kitchen premium own-brand range, backed by partnerships with five top British chefs.

Asda announced a drive to improve the quality of its foods last year in a bid to improve sales growth lagging main rivals.

The chain said the deal with Leiths was part of its goal, announced in April 2010, to overtake J Sainsbury and become the country's second-biggest food retailer.

While Asda already has larger annual revenues than Sainsbury, that is because it sells more general merchandise products like clothing and electrical goods.

(Reporting by Mark Potter; Editing by Dan Lalor)