CAMAS Aggregates is set to axe 85 jobs, with more than half lost from the heart of its quarrying operations in Devon and Cornwall.
The firm claims its plans to reorganise its business result from the savaging of the governments roads programme.
The cuts amount to 10 per cent of the companys workforce. But Camas said the reorganisation would mean that all its quarries remain open with the exception of Rockbeare Quarry.
Managing director Philip Bowden said: If we are to maintain our strong competitive position in difficult trading conditions we have no choice but to adapt the size of out workforce to reflect the falling demand for construction aggregates.
The company had been hit by the switch of the A30 Honiton to Exeter road from the public roads programme to the Private Finance Initiative.
It was geared up to supply materials at the end of 1994, but the government decision means aggregates will not be needed before the end of this year.
The company has written to local MPs outlining the delays in spending caused by the switch to private finance and explaining why it has had to shed jobs.