The manager at Old Trafford for 22 seasons claims the cross-town rival barely registers on his radar despite being bankrolled by a billionaire Arab, who is willing to invest $250 million (euro188 million) - and more if required - to lure AC Milan midfielder Kaka.

The January signings at American-owned United, which has debts nearing $1 billion, have been limited to a couple of emerging Serbians.

But the English Premier League standings show the gulf between the sides on the pitch. United, 10-time champions since the league's latest inception in 1992, is two points behind leader Liverpool with the prospect of toppling it on Saturday with a victory at Bolton.

City, without an English title since 1968, is just two points above the relegation zone - even with Sheik Mansour's first big signing, Robinho, at the heart of the strike force since September.

"I'm not being disrespectful to City because they're not where Liverpool are or where Chelsea are," Ferguson said on Friday.

"We've got to look at the teams around us. You can only worry about the ones that are actually taking money out of your pocket or taking a trophy off you. They're the teams you worry about."

Ferguson, who has been in charge at Old Trafford since 1986, has been here before. Russian billionaire Roman Abramovich bought Chelsea in 2003 and authorized an immediate spending spree, which delivered two English titles. But with Abramovich latterly adopting a more austere approach to transfers and rarely attending matches, the Red Devils have got the better of Chelsea in the last two English title races and in May's Champions League final on penalty kicks.

The 67-year-old Ferguson has seen off three managers in the process, with the fourth, Luiz Felipe Scolari, already under pressure in his debut season after Chelsea slipped to third.

"The one thing about being here is that it doesn't matter what happens, there's always a challenge," Ferguson said, striking a relaxed pose at United's training ground, leaning back in his chair, arms folded behind his head. "It doesn't matter where it comes from, you have to accept the challenge.

"We have to accept that you don't get your own way all the time. That's fine, but what you can do is make sure you're aware of your challenge and what you're going to be doing. We'll make sure we're in there pitching away and making sure we're one of the best."

By signing Kaka, though, the 2007 world player of the year could help to attract other stars at City. "It was Robinho first and Kaka next," Ferguson said. "It can encourage other players to join."

That was despite City's last major triumph back in 1976 – and that was the League Cup, English football's second-tier knockout competition.