The decision spells the end of Ogilvy & Mather's 12-year hold on the account, although O&M will continue to produce ads for the core Lucozade Energy brand and other GSK consumer healthcare.
TBWA\London also pitched unsuccessfully for the business.
"The increasingly competitive nature of the sports nutrition market gives us an opportunity to fundamentally reassess our advertising for Lucozade Sport in the UK," said Fiona Vigar, Lucozade's marketing director.
Vigar said M&C Saatchi had been briefed to communicate "the unique science-driven qualities" of Lucozade Sport in a "new and innovative way" but declined to give further details.
The brief includes the Lucozade isotonic sports drink and a growing portfolio of spin-off products from GSK. In the middle of last year it launched a 'carbo-gel' energy boost product and it recently emerged that GSK was planning a Lucozade Sport Energy Bar.
Lucozade Sport's advertising has most recently featured England and Liverpool footballer Michael Owen being trained by an eccentric coach. Previously it starred former England captain Alan Shearer.
A new sports star is expected to be added to coincide with the new advertising campaign.
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