The 'autumn of sport' promotion is timed to coincide with a series of England football internationals, Euro 2008 qualifiers and the Rugby World Cup.
The free bet will be open to customers who purchase any promotional pack of Carlsberg, Carlsberg Export, Tetley's Smoothflow or Tetley's Original, from August 13.
Consumers will be able to immediately redeem the promotion by visiting a unique webpage.
Millions of packs of beer will accommodate the offer, and the promotion will be pushed in-store, at nationwide Coral outlets, and via newspaper ads. The promotion is also set to be rolled out in pubs and bars in the future.
Richard Jaques, head of marketing for Coral.co.uk, said: "A free online bet will enhance the experience for the millions of fans who enjoy watching the action from the comfort of their home."
Ged Lowry, head of customer marketing at Carlsberg UK, said: "Retailers who communicate big sporting events will create more impulse beer purchases. This promotion offers an opportunity to build awareness and theatre for the Autumn of Sport in-store."
Both companies have along-standing history of sport sponsorship. Coral.co.uk is the official betting partner of Rubgy League's Guinness Premiership and Fulham Football Club, while Carlsberg is the official sponsor of Liverpool FC and was a founding partner of Wembley Stadium.