China clay is mainly used to coat and whiten paper

Imerys is set to make about 80 compulsory redundancies among its job cuts. A number of staff have now been given 12 weeks' notice.

Managers said many staff had already found new jobs and others had taken voluntary redundancy.

Imerys has started to wind down operations at Par Docks as it prepares to move some of its business to Brazil.

The French-owned company said the cuts were necessary and would help ensure the future of the rest of its operations in the South West.

'Floating figure'

Imerys is to close one of its seven china clay pits in the St Austell area.

One refinery and two drying units will also be closed in Cornwall; and a pit at Lee Moor - north of Plymouth in Devon - will also close, along with its refinery and drying unit.

Imerys is the biggest employer in Cornwall, employing about 2,000 people.

It is not known how many staff have been issued with 12-weeks' notice.

A company spokesman said the number of compulsory redundancies was a "floating figure" that was changed weekly, as some staff sought alternative employment.

No union officials were available to comment.

The company is the world's largest producer of china clay, operating in 250 locations in 43 countries.

China clay, or kaolin, has a variety of uses, but is mainly used to whiten and give a glossy coating to paper.