STRIX, an Isle of Man based company that is the world's biggest maker of kettle thermostats, is entering the water purification business through a deal with two Chinese kitchen appliance producers.

The private company - which is 40 per cent owned by HSBC - hopes that within three years the move will add a further 10 per cent to its sales of £80m in 2002. STRIX is planning that household water purification devices based on its design will be launched in the next few months, retailing between $30 and $40 (£20-£25).

They will sell mainly in south-east Asia, where tap water is often considered not safe enough to drink unless purified, although some related products could also enter the shops in Europe.

The Chinese companies that have been signed up to make the products to STRIX's design are Eternal and EUP. They are among China's largest kettle makers, although they rarely sell under their own brands.

The water purification products are likely to go on sale under the brand names of better-known businesses such as Haier and Little Swan, two large Chinese kitchen appliance groups.

Other European-owned appliance companies including UK-based Morphy Richards and Kenwood - owned by Ireland's Glen Dimplex and DeLonghi of Italy - could also sell purification devices based on STRIX's ideas, according to industry observers.

STRIX says the new devices - looking similar to plastic kettles - will be easier to use and give purer water than most competing appliances. These are predominantly based on purifying water through filters, rather than the combination of filtration and boiling used in the STRIX design, which it said guaranteed the removal of harmful bacteria.

Eddie Davies, chairman and part owner of STRIX, said that within three years he hoped the market for the products could reach 1m a year. "After this, the market could take off; it could be enormous."

STRIX will make money from the products by selling electronic controls to appliance makers, based on its existing designs of kettle thermostats, plus a new type of filter it has invented.

The company, established in 1981, has 400 employees in the Isle of Man and northern England, and 600 in China - where it bases most of its manufacturing. It has had a strong presence in China, which is the world's biggest centre for kettle manufacturing, since the late 1980s.

STRIX's pre-tax profits are estimated at £10m for 2002, a rise of 30 per cent on the previous year.