The advertising giant, WPP, has dropped its plans to take over UK rival Aegis, ahead of a deadline for any bid.
WPP, led by Sir Martin, is the world's second largest advertising firm
WPP had been considering a joint offer for Aegis with private equity firm Hellman & Friedman.
The UK Takeover Panel had given the two until midday on 25 November to submit an offer.
Companies owned by media agency Aegis specialise in buying advertising space and planning marketing campaigns for their clients.
After the announcement, Aegis shares fell 3.3% while WPP shares gained 2%.
"WPP announces that it has no intention to make an offer for Aegis," the group said in a statement to the London Stock Exchange.
Last month, the WPP chief executive, Sir Martin Sorrell, said Aegis had not supplied enough information for his company to make any decision on a bid.