WPP CEO Sir Martin Sorrell has joined his first social network in LinkedIn taking the chance to have a dig at the Omnicom-Publicis merger and state they want to grow digital revenues to 45% by 2018.

The often-outspoken head of what is currently the largest marketing services holding company has until now eschewed social networking, but used his first post as a LinkedIn influencer to praise the network for turning from platform to content owner.

In the post he takes a veiled dig at Omnicom and Publicis, saying: “Others in our industry may take strategic leaps backwards for various odd or inconsistent or contradictory reasons. We’ll remain focussed, actually even more focussed, on our long-established and consistent strategy, on future developments and on accelerating implementation.

“That’s how we’ll really add value to our clients’ businesses – while others find themselves distracted by internal stresses and strains.”

If the merger is successful the new group would eclipse WPP as the world’s largest marketing group.

He also looks at the company’s strategy, saying is aiming to raise its revenues from emerging markets and “new media” from 30-35% currently to 40-45% in the next five years.