Real Madrid have asked sponsor Adidas to double to €60 million the amount it pays the club annually, in view of their signing of a host of new stars, a Spanish newspaper said.

Real's new president Florentino Perez is seeking the renegotiation of its contract with the German sporting goods manufacturer, which runs until 2012, El Pais said, quoting sources close to the club and to the sponsor.

It said a refusal by Adidas, which produces and sells the club's shirts, could push Real to take its business to the company's US rival Nike.

Besides adidas, Real has several other sponsors, including Coca-Cola, Audi, Bwin and Telefonica, which altogether pay them some €130 million a year, around one third of the club's revenues of €400 million.

In the past month, Real has shelled out more than €200 million for top stars Cristiano Ronaldo, Kaka, Raul Albiol and Karim Benzema.

Perez wants to up the club's turnover to €500 million, partly so he can cover the huge salaries of €10 million a year promised to Ronaldo and Kaka and to pay for more signings, El Pais said.

"We are the best club in the world," Mr Perez told Adidas CEO Herbert Hainer in a telephone conversation seeking a renegotiation of their contract, according to El Pais.