Former England captain David Beckham has denied his £128 million move to the United States is purely for money, saying he wants to boost the game's popularity.

The multi-millionaire footballer is to play for LA Galaxy in a massive £128 million deal, it was announced yesterday. The deal will see him earn more than £70,000 a day. The five-year deal is bigger than anything any footballer has signed and experts believe it will also help protect Beckham's status as a global marketing brand.

But his decision to turn down a host of major British and European clubs may be seen by some as the beginning of the end of his career as one of the world's top players. "People will be turning round saying, 'He is only going there to get the money'. It is not what I am going out there to do," Beckham, 31, said. He said the decision to join the club had been "extremely difficult" but he was excited by the challenge of "growing the world's most popular game" in a country where it has little status compared with American football, baseball or basketball.

The move should also appeal to Beckham's pop star wife Victoria, who counts Tom Cruise's new wife Katie Holmes among her Hollywood friends. Beckham quit as England captain following last summer's disappointing World Cup and has fallen out of favour with Real Madrid coach Fabio Capello.

New England manager Steve McClaren has also snubbed the former favourite, failing to even consider him for friendlies. Beckham joins the illustrious list of football stars, including Pele and Franz Beckenbauer, to spend their twilight years plying their trade Stateside.

He added: "After discussing several options with my family and advisers to either stay here at Madrid or join other major British and European clubs, I have decided to join the Los Angeles Galaxy and play in the MLS from August this year.

"I am proud to have played for two of the biggest clubs in football and I look forward to the new challenge of growing the world's most popular game in a country that is as passionate about its sport as my own." Timothy Leiweke, the president and chief executive of Anschutz Entertainment Group (AEG), which owns LA Galaxy, has said Beckham is the only person who can make football truly popular in America. "David Beckham will have a greater impact on soccer in America than any athlete has ever had on a sport globally," he said.

The player's move comes after huge speculation about his future, with reports he would quit Real Madrid if he were not given a regular starting place. He will now leave the Spanish giants in June, four years after joining the big-spending "galacticos" from Manchester United, during which time the club has failed to win a trophy. He will play in Major League Soccer from August.

MLS Commissioner Don Garber said the move would see football generate an "unprecedented level of excitement and popularity" in the US. But some observers saw it as a clear acknowledgement that Beckham was now more of an asset off the pitch than on it.

Stuart Whitwell of brand consultants Intangible Business has said: "He has seen that he is not the star any more and it is probably difficult for a sportsman to accept. But he has got other things that other sportsmen don't have." Beckham's deal was brokered by his sports agents CAA Sports and former Spice Girls manager Simon Fuller's 19 Entertainment.

The player already has close ties with LA Galaxy's owners AEG through his US soccer academy, which he set up with the company in 2005 and shares the team's base at the Home Depot Centre in Carson, California. AEG is owned by billionaire leisure industry mogul Philip Anschutz, and is also involved in redeveloping London's Millennium Dome.