The canyons of Wall Street and Madison Avenue reverberated with speculation following Friday's announcement by Interpublic Group that it is to revise downward by $514 million (€426m; £290m) its net income over a period extending back several years.

Adjustments to a raft of accounting errors obliterated the only profit posted by Interpublic since 2001 and increased losses reported for other years.

The world number three agency holding company also released its long-overdue financial reports for 2004 and the first half of 2005 - frozen earlier this year after the discovery of "material weaknesses in internal controls".

In the same statement, IPG quantified the sum it expects to return to clients for reasons of "malfeasance" in certain overseas operations (notably Turkey, Greece and Bulgaria).

But of the $200m expected to be handed back to clients, only some $56m is attributable to fraud. The guilty parties had been dismissed - but the statement made no reference to criminal prosecutions.

Recently appointed chairman/ceo Michael I Roth told the Wall Street Journal he plans to spend more time unravelling myriad issues within the company's operations. In particular, he'll be taking a long hard look at the ailing Lowe Worldwide agency, whose clients include GM and Unilever. But he insists he is not considering the sale of any major assets.

Roth warned the group still confronts major problems, not least resolving the flaws in its financial reporting systems. He also said the accounting probe by the Securities and Exchange Commission remains ongoing.

The statement has triggered a tsunami of speculation as to whether, in the face of restatements totaling $514m plus a $200m payback to clients, IPG as a holding company can survive in its present form.

Data sourced from Wall Street Journal Online; additional content by WARC staff