The confectionery giant, founded in Birmingham in 1824, is to become the second tier two Supporter in a deal worth an estimated £20 million.

The deal will be effective immediately, giving Cadbury the designation of official confectionery and ice cream supporter for London 2012, rights to use the London 2012 marks on product as well as marketing rights to Britain's Olympic and Paralympic teams. 

At Games’ time, Cadbury will supply all confectionery and packaged ice cream sold at venues and within the Olympic Park. 

Cadbury was also an official supplier of the Sydney Games in 2000, as well as the Commonwealth Games in Manchester in 2002 and Melbourne four years later.

The Bournville-based company becomes London 2012’s second tier two supporter, following the announcement of Deloitte as professional services supporter at the end of last year. 

But the latest deal is set to be controversial because it will anger health campaigners who claim that using the Olympics to promote chocolate is against the ethos of using the Games as an opportunity to help get the nation healthier.

London 2012 chief executive said:  “Following the success of Team GB and ParalympicsGB this summer, we all came back from Beijing with a spring in our step and this has been replicated in the commercial sector - there has been a surge of interest in London 2012 and I’m thrilled that Cadbury - another great and trusted British brand - has come on board.

"They have a great track record supporting both major sporting events and community initiatives and we welcome them to the London 2012 family.

"This is another fantastic achievement for the commercial programme and with this deal we have now raised over £430 million, which is well on our way to our domestic sponsorship target [of £600-£700 million] as we seek to raise the £2 billion required to stage the Games in 2012.”

Todd Stitzer, the chief executive of Cadbury, said: “For nearly 200 years, Cadbury has been part of the fabric of British life so we are extremely proud to be a sponsor of the London 2012 Olympic Games and Paralympic Games.

"Since John Cadbury opened a chocolate shop in Birmingham in 1824, we have strived to be a company that is both performance driven and values led – a philosophy that is at one with the long-held ethos of the Games: inspiration, optimism and community.

"London 2012 is a huge opportunity for us all to celebrate everything that is great about Britain and to bring local communities together throughout the UK .

"We look forward to building on all these things through our existing community partnerships.

"The Cadbury brand reaches every corner of Britain .

"The Games has the power to excite and inspire, and by working together we can bring a bit of fun and magic to everyone’s lives. “

Among the athletes that Cadbury have used to promote their past sponsorships are 2000 Olympic hepathlon champion Denise Lewis and marathon world record-holder Paula Radcliffe.

Rebecca Adlington, the two-time Beijing Olympic swimming champion, is expected to be the main face of Cadbury sponsorship in the build-up to London 2012.

London 2012 currently has signed seven tier-one sponsors - Adidas, British Airways, BP, BT, EDF Energy, Lloyds TSB and Nortel - and one tier-two partner, Deloitte.

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