The media and creative accounts for the water and electricity supplier were put up for statutory review at the end of last year. Leeds-based Poulter Partners won the creative account from Manchester's Cheetham Bell JWT in February.
MediaCom North has won the media contract for a further three years.
United Utilities does not own any retail business but has undertaken corporate branding campaigns in the North West of England promoting its business. It is also the sponsor of ITV's regional weather bulletins in the Granada region.
Catherine Hayes from United Utilities said: "I was very impressed with the quality of the media strategy proposals put forward by MediaCom North and I'm pleased that the team at MediaCom North will be continuing to work on our account."
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