AMBITIOUS plans are under way to extend the life of a potash mine by another 40 years, create hundreds of new jobs and make a £300m investment.

The discovery of vast deposits of the fertilizer mineral under the North Sea has led Cleveland Potash to bid for an extension of planning permission at its Boulby site in East Cleveland until 2063.

Cleveland Potash's parent company ICL (Israel Chemicals Limited) has also approved a 300m investment over the next five years to install state of the art underground equipment, as well as revamp the Boulby plant and its Teesport loading facility.

To support its expansion plans the company expects to recruit 120 new workers this year and another 100 by the end of 2015, taking staff numbers to about 1200.

It is about to start discussions with the North York Moors National Park Authority to extend its current planning permission, which runs until 2023, for a further 40 years, as well as taking up the option of a 20-year extension to its lease at Teesport which expires next year.

If the plans get the go ahead it could secure jobs for the next generation of mineworkers.

Phil Baines, the companys general manager, said: "Cleveland Potash has been East Cleveland's biggest business and biggest employer for many years and this announcement makes clear we will be here for many more years to come.

For the workers we have here now it would mean jobs for their children and their grandchildren.

North East Chamber of Commerce chief executive, James Ramsbotham, said: "Hundreds of people rely on Cleveland Potash for their income and it is a real driver of the local economy with two and sometimes three generations of the same family working down the Boulby mine.

I am delighted that the long-term future of this blue chip regional company can be secured with this project."

One of the first steps will involve a 16m programme this summer to replace the Rock Shaft Head Tower at Boulby which will increase its production potential by one million tonnes a year.

The Boulby mine has been producing the potassium-rich salt mineral since 1973. Used almost exclusively in the production of agricultural fertilizers, about one million tons of the potash is extracted each year, half of the UK's total output.

The mine also produces rock salt, used as a de-icing agent on roads in winter conditions.

"Our plan is to extend operations out to the east in parallel to the area worked over the past 40 years-effectively providing a new mine for the next 40 years, added Mr Baines, who said the new discoveries were made after the Israeli owners approved a rapid acceleration of exploration activity, including a 4m offshore seismic survey.