This follows an investigation by the board’s audit committee that found that five transactions entered into in 2000 and 2001 were accounted for improperly. These deals range in size from $800,000 to $2.4 million, and the committee concluded that revenue in 2000 and 2001 was overstated, while revenue in 2002, 2003 and 2004 was understated.

The committee said it is close to completing its review of transactions between 2000 and 2002, and is also evaluating transactions entered into in 2003 and 2004. It also warned that the final result might vary significantly from its preliminary assessment.

Aspen has shown little growth over the past three years, and in the year to June 30, 2004, it reported a net loss of $35 million on revenue of $325.6 million. The company is also appealing against a decision by Nasdaq to delist it for failing to file with the SEC figures for its first quarter to September 30. An extensive process of recalculating past years’ figures is likely to delaying the filing still further.

CFO Charles Kane is to take over as interim CEO while a search is launched for a permanent replacement.