The agency beat Adam & Eve/DDB, Creature and VCCP and is tasked with creating an integrated campaign that will air in 2015.
Bartle Bogle Hegarty was the incumbent on the account, but did not re-pitch. BBH still handles several other Britvic drinks brands, including Robinsons and J20.
Howell Henry Chaldecott Lury helped launch Tango in 1992 and created some of its most famous ads, including "st george" for Blackcurrent Tango in 1996.
Phil Rumbol, one of 101’s founding partners said: "There are few tasks you can genuinely call 'once in a lifetime', but this one certainly fits the bill.
"Tango’s back catalogue of advertising is truly enviable, but it’s the Britvic team’s energy and determination to produce outstanding communications that makes this a special moment. We’re flattered and delighted that they’ve chosen us to help them realise this opportunity."