Following a 10-month wait for the figures to be confirmed, Nortel revealed that it had made $434m (£231m) compared with its previously-stated figure of $732m.

The restated figures reflected understated losses for both year-ends 2001 and 2002.

The forensic accounting arm of Huron Consulting was drafted in to assist Nortel's audit committee's review to gain a 'full understanding of the events that caused significant excess liabilities being carried out on the company's balance sheet that needed to be restated, and to recommend to the board of directors the adoption of necessary remedial measures to address personnel, internal control, compliance and discipline issues'.

An investigation by the audit committee is ongoing, and Susan E Shepard has been appointed to the recently created position of chief ethics and compliance officer.