One hundred and fifty workers are to lose their jobs at Marconi plants in Essex and Northamptonshire, union leaders have revealed.

The job losses are part of the sale of the troubled electronic firm's optical components division to Bookham Technologies.

The Manufacturing, Science and Finance union, the MSF, said voluntary redundancy would be offered to all workers.

The bulk of the losses will go at the firm's plant near Towcester in Northamptonshire.

Debt reduction

The announcement came at the end of talks on Thursday between management and union representatives over the future of jobs at the two plants in Caswell, Northamptonshire, and Chelmsford, Essex.

The majority of the jobs will go at Caswell, as the Chelmsford site only employs around 50 workers.

The sale is part of a programme begun by Marconi to reduce its debts of about �3.5bn.

The company reported a loss of �5.1bn ($7.1bn) during the six months to September, one of the greatest corporate losses in history.

The deal to sell both sites to Bookham Technology, an optical components business, is valued at �19.7m.