Unilever, the Anglo-Dutch consumer goods group, has signed the biggest airtime tie-up in UK television history with a four-year, £320 million deal with Carlton Communications and Granada to advertise products such as Dove soap and PG Tips tea, reports Reuters.

The contract between Unilever and the broadcasters that run Britain's biggest commercial TV network, ITV, comes amid a push by advertisers to get discounts of up to 25 per cent through long-term deals.

The contract provides guaranteed revenue for Carlton and Granada during a TV advertising slump, blamed in part on the collapse of dot-com companies as well as sagging confidence in using television to sell products.

"It gives us a good deal for the money," Unilever spokesman Trevor Gorin said of the contract, adding that it offered "a considerable saving". He declined to comment on specifics.

Unilever is the United Kingdom's top advertiser and spends more than £120 million a year on leading brands such as Flora margarine, Persil washing powder and Lynx deodorant.

The four-year contract with the ITV broadcasters replaces similar deals that were renewed each year, Gorin said.