Marconi has revealed plans to cut a further 4,000 jobs from its workforce.
The group says it expects year-end sales to be around 15% lower than last year and operating profit before exceptional items to be down by approximately 50%.
Marconi says it will also take steps to shed a further 1,000 management jobs.
The group's revised outlook follows its decision to sell off one of its businesses and suspend its shares.
Philips has agreed to buy Marconi's Medical Systems business for £780m.
The new restructuring programme will result in a further exceptional charge of £150m and is expected to save a further £150m on an annualised basis and £75m in this financial year.
This will bring the total restructuring charges for the current year to £550m, saving £350m on an annualised basis, and £200m in this financial year.
In total, including the transfer of employees to Jabil Circuit within the framework of the company's outsourcing programme, this will lead to a total headcount reduction of over 10,000.
A company spokesman said: "Market conditions during the first three months to June have been much tougher than expected.
"Whilst customers continue to show operational interest in solutions and continue to request information, in recent weeks it has become clear that financial constraints in the service providers, particularly in Europe, are now causing that interest to not convert into firm orders at the usual rate."