Channel 4 and Group M, the media buying arm of Sir Martin Sorrell”s WPP, have ended their dispute and agreed a new trading agreement. The wrangle emerged before Christmas when Group M refused to accept Channel 4”s proposed rates for a 2013 deal, leading to the agency pulling all advertising from the TV channel.

Group M”s clients buy about a third of all UK TV advertising, and include brands such as Barclays, EE and Ford. During the dispute, ads were pulled from the channel and UK TV advertising rates distorted, such as rivals ITV pushing up their rates.

The new agreement means that advertisers who left the channel will appear again, once more.

In a joint statement Jonathan Allan, Channel 4′;s Director of Sales and Mark Collins, Group M Managing Director Broadcast Trading, said: “Negotiations are necessarily long and complex when two major media companies want to agree commercial terms in a complex and fast moving environment, but we were both very focused on getting things right for all parties.

“We look forward to building on our strong relationship and working together closely to deliver business and marketing success for all our mutual clients.”