Cordiant advertises some of Britain's best-known brands

Cordiant's board has agreed to a tie-up with rival advertising group WPP, but shareholders are voting on the issue on Wednesday.

Active Value, a UK investment fund which owns 28% of Cordiant, is reported to be gathering support for a concerted attempt to block WPP.

French advertising group Publicis has admitted meeting Active Value on Saturday to discuss a possible tie-up.

Contact denied

But the French company, which last month dropped out of the running for Cordiant, said it was still not interested in making a full bid for the company.

It said it remained interested in its options regarding Cordiant's media buying arm Zenith Optimedia in which it has a 75% stake.

"UK Active Value made a proposal regarding Cordiant and Cordiant's shareholding in Zenith Optimedia Group, which Publicis declined," Publicis said in a statement.

"Publicis confirms that it has no intention of making an offer for the shares of Cordiant and that it remains interested solely in the Cordiant assets to which Publicis is linked by shareholding, by a brand belonging to Publicis or through clients which have selected Publicis."

In a separate twist, a source close to the situation told the Reuters news agency that another Cordiant shareholder Nahed Ojjeh, a wealthy Paris-based chess patron, increased her stake in the firm late on Friday.

Mrs Ojjeh picked up a large block of about 775,000 shares and raising her 9.89% stake to more than 10%.

Publicis has denied any contact with Mrs Ojjeh, as have Active Value.

Investigation

Cordiant has an option to sell its 25% stake in Zenith to Publicis at �75m but a change of control at Cordiant could trigger a sale at a much lower price, based on 25% of the Cordiant equity.

Industry watchers think Active Value and Mrs Ojjeh are seeking to take control of the struggling ad firm to help Publicis buy Zenith at a knock-down price.

In return, Active Value and other shareholders could share the savings Publicis makes from buying Zenith on the cheap.