Procter & Gamble has signed the costliest sponsorship agreement in its history, and will back the National Football League from the beginning of next season.

Though the company would not give financial details beyond saying that it was the most expensive in its history, a source close to the deal claimed that it is worth at least US$10 million per year to the league over the next three years.

The deal gives P&G the right to use the red, white and blue NFL logo on a whole range of its products. The league has 20 other major marketing partners.

"When we acquired Gillette, we found out how much of a role sports marketing could play with our broader P&G portfolio," said Jason Dial, P&G's director of global sports marketing. The company now spends more than US$90 million per year in US sport sponsorships.