A hacker broke into systems at JDS Uniphase yesterday, gaining access to confidential documents hours before the fibre optic firm was due to issue its fourth quarter financial results.

It is believed the hacker gained access to a draft of the company's fourth quarter report, in which JDS announced losses of $477m on sales of $601m. The security breach was bad enough to force JDS to call Nasdaq to halt trading on its stock.

The official results were released at close of trading yesterday, revealing more job cuts. JDS has already cut 9,000 positions last month, but the company said it would axe a further 7,000. Aside from the $477m losses, the firm announced a cumulative $44.8bn write off of assets for the fiscal year, reportedly the largest ever corporate loss.