Sorrell abandoned a deal to buy Aegis with US private equity partner Hellman & Friedman in November. The plan, if successful, would have seen WPP take control of the Aegis market research firm Synovate and take a small stake in the remaining media buying business.
WPP could still bid again after the deadline for its original bid passed on November 25, but under UK takeover panel rules it must now wait until May.
Speaking to Reuters, Sorrell said: "The idea was that we would have a small stake in the media organisation and would buy Synovate, and we are interested in that."
However, Sorrell said that before a deal could be done WPP would have to look closely at Synovate's books. He questioned whether the data seen last time was exact, suggesting it was overly bright.
"We would have to have a very close look at Synovate. The information we were given I do not think was accurate. I think it was probably very optimistic," he said.
While he would not be drawn on the intentions of Vincent Bollore, Havas chairman, who is the largest shareholder in Aegis with a 25.47% stake.
What Sorrell did tell the news agency was that he, like the rest of the ad industry, doubted that Aegis would stay independent for very much longer.
"I don't think Aegis will remain independent," he said.
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