Marconi, one of the world's biggest telecom equipment makers, has told investors it will issue a trading statement expected to indicate how the group is faring in an industry-wide slowdown.
In an extraordinary step, the group also sought and received a trading suspension in its shares pending the anxiously awaited announcement after a board meeting later in the day.
Marconi, which earlier announced the $1.1 billion sale of its medical systems business to Philips Electronics, said it had requested the suspension to "ensure that investors have full information before trading recommences".
A spokesman declined to say what time today's board meeting would start. A trading statement would be issued when it was over, he said.
Marconi's stock has been buffeted in recent weeks by broker downgrades, profit warnings by rivals such as US Tellab and a plan to reprice staff share options that has found little favour with investors.
Marconi shares closed at 245p yesterday - near their lowest level since the firm's creation in 1999 - after Morgan Stanley became the latest investment bank to cut its share price target for the group.
The bank noted market conditions were "difficult" and that there was uncertainty surrounding Marconi's performance.