The company said it was consolidating its operations

Chief executive Gerard Buffiere said on Wednesday that Imerys would invest in its Devon and Cornwall facilities and did not intend to move out of Britain.

Last month the firm announced nearly 800 jobs are to go at Cornwall and Devon pits in a reorganisation.

Imerys said the changes were needed to protect the future of its business. Unions are to fight the redundancies.

Mr Buffiere said the English operations were well-suited to producing kaolins, minerals whose uses include making glossy paper.

He told investors in Paris: "England is a durable unit."

Brazil move

More than 700 jobs will go in Cornwall as operations are consolidated and up to 85 jobs in Devon as the company closes its pit at Lee Moor.

Some of the current operations carried out in Cornwall will be moved to Brazil in late 2007.

A �69m (100m euro) investment programme will be rolled out to improve facilities in Cornwall and increase production capacity at its Brazil plant.

Imerys blamed high energy prices, a weak dollar and strong overseas competition for significant losses.

The redundancies amount to almost half of the French company's 2,000-strong workforce in the region.

Imerys took over the long-established English China Clays in 1999 for �756m.