Manchester United has officially confirmed to the London Stock Exchange that it has accepted a £623.4m bid from Rupert Murdoch's television company, BSkyB.

It is the largest amount ever offered for a sports club.

Manchester United's Chief Executive Martin Edwards: 'The management of the club will remain as it is'

The move comes despite an outcry from fans and the threat of a high profile government investigation into the deal.

However BSkyB and Manchester United defended the deal, denying that they would betray the club's fans and hailing the deal as one of the 'great partnerships in sport'.

News of the higher offer caused Manchester United's shares to leap upwards again on the London stock market.

Nomura Analyst David Brooks: 'This is Murdoch's opening gambit'

City analysts believe that Rupert Murdoch's bid could spark a bidding war, with rival media group's vying for Manchester United's unique footballing brand.

The club's shares rose more than 10% to 221p in early trading, and have now soared almost 40% since BSkyB first confirmed its interest in the club on Monday.

The BBC's Bernie Rose: An insurance policy for Murdoch

The satellite broadcaster's bid is worth 240p a share and is almost £50m more than original estimates.

Manchester United share holders will receive 120p in cash and the rest in BSkyB shares. and the offer represents a 51% premium to the club's closing share price of 159p on Friday.

However David Brooks, an analyst at Japanese bank Nomura, believes that this is just Rupert Murdoch's opening gambit, and the final takeover price could be as high as 275p.

BSkyB's bid still has to be approved by shareholders and the Office of Fair Trading, which will have to assess whether or not it is in the public interest.

The BBC's Rory Cellan Jones: Rupert Murdoch played a significant part

The club is the largest in the United Kingdom in terms of support and wealth.

Its popularity has meant that it earns as much from merchandise sales and advertising as from gate receipts.

Rupert Murdoch: He owns a controlling stake in BSkyB

BSkyB, currently owns the rights to broadcast Premiership games live until 2001.

Officials from Manchester United have been locked in talks at a London business suite over the last few days discussing Rupert Murdoch's offer, amid growing opposition from fans.

Murdoch involved in talks

'Shareholders United Against Murdoch': spokesman Richard Lander on BBC Radio 5 Live

Wednesday's edition of the Rupert Mudoch-owned 'The Times' says the media magnate was himself involved in the talks in London.

The paper says BSkyB was forced to increase its bid after two Manchester United directors reckoned the club was being under-valued.

Rich pickings

Martin Edwards: Set to make nearly £90m under the deal

Martin Edwards, United's chief executive and largest single shareholder, is set to see his 14% stake in the club increase in value to £87m.

The figure represents about £30m more than if he had sold his shares on the open market on Friday.

Another winner will be non-executive director Maurice Watkins who, according to the club's last company report, owned around 2% of the club.

The stake would be valued by BSkyB under the deal at just over £12.5 million, up from just over £8 million on Friday.

Opposition to sale

The BBC's Rory Cellan-Jones: "Peter Mandelson faces a political dilemma"

Secretary of State for Trade and Industry Peter Mandelson, has said any offer would be examined "very completely and extremely searchingly" by the Office of Fair Trading.

FA chief executive Graham Kelly said United had to explain the deal to its fans, adding: "We have to assess the implications very closely indeed."

Key deal for Rupert Murdoch

Chief Executive of BSkyB Mark Booth talks to the One O'Clock News

The takeover project was driven by Mark Booth, chief executive at BSkyB, in which Mr Murdoch's News Corporation owns a 40% stake.

It sprang from a lunch with United chief executive Martin Edwards, who himself stands to make £87m from his 14% stake in the club.

BskyB, Britain's most profitable broadcaster, has invested heavily in sports programming.

It paid £670m for the right to broadcast live football matches in 1996.

But those rights run out in 2001 - and by then some of the big clubs may want to sell their rights individually.

MU TV is the club's recently launched TV station

And Manchester United have recently launched its own television station.

Looming over the deal is the question of pay-per-view television.

By some estimates the bigger clubs like Manchester United could share a bonanza of up to £2bn if fans had to pay a fee to watch each match rather than a fixed fee to BSkyB.

The deal would also secure BSkyB's position if a European Super League were to go ahead, combining the best clubs in Europe.

Manchester United would be certain to be included in such an arrangement.