Sources said talks had taken place between Omnicom and The Search Works, but that a deal had not yet been agreed.
The Search Works has built a working relationship with Manning Gottlieb OMD in the UK, but the Omnicom agency has also developed its own search resource; a deal with The Search Works would boost its search capability.
The company is understood to have held discussions in the past with other media groups, which came to nothing.
One potential barrier to a deal is said to be the premium the business commands. Omnicom is not keen on acquiring businesses based on a high multiple of earnings.
Jim Brigden, the managing director of The Search Works, said: "We do get approached every day, but we are not looking to sell."