The news came as Corning, one of the biggest makers of components for optical communications networks, said it would cut another 1,000 jobs. Telecoms analysts also suggest Lucent, which recently offered many of its US managers a buy-out package in an effort to shed around 5,000 jobs, is also gearing up for another round of forced job cuts.

All three companies have already cut staff numbers this year but have been forced to act again as consumer demand has slumped even further. Corning had previously forecasted sales of its optical products to double to $2bn this year, but said on Monday that they now looked likely to fall by a staggering 30-40% instead.

Lucent and Alcatel recently dropped plans for a merger that was meant to help them manage the slump in telecoms industry more easily. That deal would have been followed by extensive job losses to slice $4bn from their combined costs.

Acting alone, Alcatel on Monday announced the most severe of three separate job-cutting moves this year. The latest cuts will reduce its US headcount to 12,500, about 27% lower than it was at the beginning of the year. Some 800 of the jobs will go at Alcatel’s US headquarters in Plano, Texas, with an additional 700 jobs to be cut at a factory in Raleigh, North Carolina.

Corning said that its latest round of job reductions would take the total cuts this year so far to 5,900, or 15% of its total workforce. It is also to close three manufacturing facilities in the US.

In an echo of big write-offs that have been taken by other makers of communications equipment, Corning said it would take a $5.1bn pre-tax charge against its earnings for the second quarter.

Some $4.8bn of the charge has been prompted by a write-down of goodwill and other intangible assets linked to two acquisitions made last year, when optical stocks were soaring. The collapse in share prices since then has forced similar hefty charges at other companies, including a $19bn write-down last month at Nortel Networks, the Canadian equipment maker.

Corning also said it would write off $300m of excess inventory and abandon paying a dividend to shareholders. The company added that earnings in the second half of this year were unlikely to meet Wall Street’s expectations, though it did not provide further guidance.