United threaten to report Real over Ronaldo

(CNN) -- Manchester United have warned Real Madrid that they may report them to FIFA over their continued public pursuit of Cristiano Ronaldo.

The Premier League and European champions have grown increasingly exasperated with the Spanish giants and issued a statement on the club's Web site on Tuesday night to threaten further action.

"Manchester United has watched with growing irritation the comments attributed to Real Madrid over their alleged desire to sign Cristiano Ronaldo," the statement said.

"The facts are: the player is on a long-term contract and his registration is held by Manchester United; The player is not for sale.

"The club will have no alternative but to report Real Madrid to the world governing body, FIFA, if it continues to behave in this totally unacceptable fashion."

Ronaldo, who was United's top scorer with 42 goals last season, has made no secret of his desire to eventually play in Spain, but United are determined to hold on to their prize asset who has four years left to run on his current deal at Old Trafford.

The winger joined up with the Portuguese national squad, who are preparing for Euro 2008, shortly after United beat Chelsea on penalties to win the Champions League.

United also claimed that the statements emanating from Real would be a distraction for the Portuguese squad as they prepare for the championships.

Only last week United manager Alex Ferguson accused Real of "lacking morals" in their transfer dealings, comparing them unfavorably with fellow Spanish super club Barcelona.