German sports giant Adidas on Thursday agreed a sponsorship deal with NBA superstar James Harden which was reported to be worth $200 million in a major blow to heavyweight rivals Nike.

The contract for the 25-year-old Houston Rockets star takes effect from October 1 and is understood to span 13 years.

Adidas said it would not divulge the value of the long-term deal although American sports network ESPN claimed it was worth $200m (180 million euros).

"From the start of this partnership, Harden is going to play a role in the worldwide promotion of Adidas which will coincide with the start of the new NBA season," said a spokesman. "He will also have a key role in creating and developing a line of sports shoes and clothing."

Last year, Adidas announced a 10-year link-up with English Premier League giants Manchester United worth a minimum £750 million (1,170 million dollars).

The group is also attempting to re-establish its foothold in North America in the face of competitors, Nike and Under Armour.