
Previously the media account was divided between OMD UK, which handled the offline account, and the specialist digital arm of Arena BLM, BLM Quantum.
Both incumbent agencies pitched for the business alongside ZenithOptimedia and WPP's Mediaedge:cia.
The six-year-old 118 118 is expected to launch a vigorous marketing push in the UK, which will be led by a UK chief marketing officer yet to be recruited.
Earlier this year, the company implemented a global restructure, which made the role of European chief executive, held by Mark Horgan, redundant.
The company has also consolidated its advertising accounts, resulting in the company cutting ties with WCRS and Naked, in favour of The Brooklyn Brothers.
118 118 is currently sponsoring TV programme The Simpsons as it looks to expand its sponsorship presence.