Before the review, the company's media business had been divided between OMD UK, which handles the offline account, and the specialist digital arm of Arena BLM, BLM Quantum. Naked Communications has also handled parts of the business in the past.
Both incumbents were involved in the review's final list of competing agencies and were joined by WPP's Mediaedge:cia.
Other agencies believed to have been dropped from contention at an earlier stage include WPP's remaining networks Maxus, Mindshare and MediaCom, and Publicis Groupe's Starcom.
The protracted five-month pitch process was handled by intermediary Oyster Catchers and was led by 118 118's chief executive and former Superdrug marketer, Gerry Murphy.
In the last year, the company has spent £10.5m on media in the UK according to The Nielsen Company, and an additional £3m was ear-marked for online by one of the agencies involved in the review.
ZenithOptimedia's appointment comes ahead of an anticipated marketing push in the UK, which will be led by 118 118's first UK chief marketing officer, who is still to be recruited.
Earlier this year, the directory service business 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 six-year old company cutting ties with WCRS and Naked, in favour of The Brooklyn Brothers.
.jpg)
.jpg)