Key Points:

David Beckham has signed a £20 million ($54 million), three-year deal to advertise Giorgio Armani underwear.

The soccer superstar will appear on billboards and magazine adverts from early next year.

David began shooting the Emporio Armani SS08 campaign with renowned photographers Mert Alas and Marcus Piggott in Los Angeles last week.

It is thought David's relationship with the 73-year-old designer - who has hosted dinner parties for David and his wife Victoria since their move to Los Angeles - was "instrumental" in securing the deal.

A source close to the designer said: "The personal relationship was definitely instrumental in this deal. David and Giorgio get on very well so it was very much Giorgio's personal choice. But Armani also see this as a sound business decision - few individuals have a truly global reach that can match David's."

Father-of-three David will receive an annual fee as well as royalties for his role as the new global ambassador of the label.

While his advertising contracts with Vodafone and Gillette came to an end earlier this year, 32-year-old David still fronts campaigns for Adidas, Pepsi, Motorola and Coty fragrances.

An Armani spokesperson said: "I can confirm David Beckham will be appearing in the Emporio Armani SS08 underwear campaign."