Alex Ferguson has confirmed Manchester United have opened contract negotiations with Cristiano Ronaldo.

The Portugal winger's future has been the subject of intense speculation over the past few months, with Spanish giants Real Madrid and Barcelona among the 22-year-old's suitors.

But United are determined to keep their prize asset and are ready to offer Ronaldo a big-money contract extension following assurances the former Sporting Lisbon player wishes to remain at Old Trafford.

"Cristiano is at the right club," said Ferguson. "He wants to stay. Why should he want to go anywhere else?

"We have been negotiating for a few weeks now and hopefully we can come to an agreement where he will stay with us for the next few years."

Although it has been reported in some quarters United are offering Ronaldo £120,000-a-week, Ferguson has warned a compromise needs to be found.

Ronaldo's agent Pedro Mendes is in a powerful position, with Ronaldo now confirmed as one of the best players in the world.

Mendes will demand a salary in keeping with the youngster's present status but United, mindful of the likelihood that other top earners may want parity, will want to keep a lid on the cash being offered.

"When you are negotiating, you hope eventually a compromise situation will be reached somewhere along the line," said Ferguson.

"We want to reach an agreement because the boy has been a fantastic player for us."

Ronaldo will be part of an injury-hit United squad for tomorrow's FA Cup quarter-final at Middlesbrough, when Henrik Larsson will make his final appearance for the club.

China international Dong Fangzhuo has been called into the travelling party as Ferguson looks to cover the absences of Paul Scholes through suspension, plus Ole Gunnar Solskjaer (knee), Louis Saha (hamstring), Darren Fletcher (ankle) and Mikael Silvestre (dislocated shoulder).