Manchester United have agreed to pay Sunderland up to £3 million for David Bellion rather than rely on an independent tribunal to determine a compensation package.

The figure, though easily affordable to a club of United's riches, represents a baffling about-turn when the Football League appeals committee (FLAC) was widely expected to settle the fee at a considerably lower price.

After nine months of often acrimonious negotiations, the dispute between the clubs was due to be heard by FLAC yesterday, only for both to reconvene talks. They finally announced United will pay an initial £2 million, with a further £1 million dependent on appearances and international call-ups.

Bob Murray, the Sunderland chairman, immediately proclaimed his delight with the agreement, which includes a sell-on clause from which the Wearside club would benefit if United transfer Bellion. But senior officials at the Football League were bemused by United's U-turn, believing the club might have over-spent by as much as £1 million.

Why United appear to have backed down is a mystery given they had previously offered to pay only half of Sunderland's £3 million valuation. Supporters' groups were last night questioning why, in such a deflated transfer market, they had paid so much for a player who made only three starts for Sunderland.

Murray had previously accused United of making an illegal approach for Bellion - which United denied - and one possible explanation for the fee could be a reluctance at Old Trafford to have the full details of the transfer emerge during a tribunal.

"We're happy with the amount, otherwise we wouldn't have agreed it. It's a fair price for a promising young player," said their spokesman Paddy Harveson.

Bellion is regarded as one of the fastest players in English football, but the 20-year-old Parisian also has the reputation of an erratic finisher and has made only two substitute appearances since signing for United in July, when his contract at Sunderland expired.

When the transfer was first mooted in January, United were prepared to offer only £1.5 million, a figure which caused Murray to label them "arrogant and despicable".

Had United had been prepared to go through a league tribunal several factors would have been in their favour. As Bellion is under 24 he is not eligible to move on a Bosman free transfer, so the tribunal would have based compensation on how long the player had been at Sunderland and how instrumental the club had been in his football education. Given that Bellion had joined from Cannes only two years ago and was a peripheral player, the tribunal might not even have required United to pay a seven-figure sum.

Meanwhile, Everton deputy chairman Bill Kenwright has moved swiftly to kill off speculation that England star Wayne Rooney is set to leave Goodison Park.

The 17-year-old has been linked with a £35 million move to Chelsea, who have also denied they are lining up a move for the striker.

"Wayne Rooney is going nowhere," Kenwright told Sky Sports. "David Moyes and I sing from the same hymn sheet and always said any club would have to pay a king's ransom for a player like Rooney. He is part of the fabric at our football club.

"A talent like Wayne's comes along once in a lifetime. We are only concerned at his progress in the blue shirt of Everton. He's a Blue and wants to remain a blue."

Manager Moyes told the club's official website: "The story is complete rubbish. There is no truth in it as far as I know, and as the manager I would expect to know about something like that if it was happening."