GroupM has acquired The Exchange Lab and its proprietary programmatic marketing technology, Proteus, helping expand the capabilities of the WPP shop's Connect platform.

James Aitken, who co-founded The Exchange Lab in 2007 with Tim Webster, is stepping down from his post as CEO to pursue investment interests, according to a statement. Mr. Webster will remain onboard in his role as chief strategy officer. Chris Dobson, executive chairman of The Exchange Group, will succeed Mr. Aitken as chief executive, reporting directly to Rudiger Wanck, Global CEO of Connect, GroupM Global.

Mr. Wanck said GroupM became familiar with The Exchange Lab in the spring when the firm rebranded its digital operation from Interaction to Connect. He added that the shop fit very well with GroupM's overall ambition of "optimizing media across every property and technology and do it in an agnostic way and continue to build and grow that."

While The Exchange Lab will continue to operate on its own, it will become part of GroupM Connect's global network, allowing the firm to enhance its offerings for clients.

The Exchange Lab has about 130 staffers across its London, New York, Chicago, Singapore and Toronto offices. Some of the company's clients this year have included Virgin Holidays, Volkswagen, A&W, Glasses Direct and Vue Entertainment.

Financial terms of the deal were not disclosed.

Last month, GroupM bought independent digital media buying agency Essence Digital in a move to potentially strengthen its relationship with Google.

The Exchange Lab earned revenue of nearly $32 million for the year ended, Dec. 31, 2014, according to a statement from WPP. The statement added that WPP's digital revenue last year was $6.9 billion, making up 36% of the holding company's totally revenue of $19 billion. WPP aims to have between 40% and 45% of its revenue come from digital in the next five years.