The news comes as WPP is embroiled in cases against a former executive at its Italian operations, as well as with Express Newspapers owner Richard Desmond, over the launch of OK! in the US.
According to the Sunday Times, the French supreme court has ordered that Aegis have access to key documents at the centre of the client poaching case against KR Media and the two former Aegis executives who formed it, Bruno Kemoun and Eryck Rebbouh.
The pair are nicknamed "the twins" because they have worked in tandem for more than 20 years. They quit as chief executives of Aegis Media Europe in November 2003 and had a non-solicit clause that prevented them from talking to clients of Carat until November 2004.
Aegis has accused them of breaching this clause and is claiming €34m (£23.2m) in compensation. In December 2004, KR Media's Paris offices were raided. A month later, Aegis had its case thrown out of court, but in February 2005 it won an appeal after a court found that the KR Media defence had "serious flaws". The court's decision to grant Aegis access to papers is a blow to KR Media's defence.
Separately, Sir Martin's battle with former WPP Italy country head Marco Benatti steps up this week, as the board of Fullsix meets to discuss Benatti's €85m takeover offer.
According to the Independent on Sunday, WPP is expected to move to thwart Benatti's takeover. Benatti was sacked by Sorrell in January because of his failure to disclose that he owned a stake in Media Club, an agency bought by WPP. Benatti is countersuing because of the damage to his reputation.
The Sunday Telegraph reports that WPP's investigation into fraud at its Italian operations is being expanded to cover BRW, a television production company used by WPP. It is thought that there are financial links between BRW and Benatti.
WPP's 2005 results are to be published on Friday.
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