The contract will terminate on 23 August, but it is anticipated that the group will continue to manufacture, sell and distribute Rockstar energy drinks up to 1 November 2020.
In accordance with the terms of the contract, a one-off compensation payment will be paid to the AG Barr.
Earlier this week, Rockstar revealed it is reformulating its core range with 25% more caffeine. AG Barr has held the Rockstar contract since the brand entered the UK market in October 2007.