In a statement issued to the market at 7.59am, the two boards outlined details of the deal.
The offer is in cash and shares. BSkyB will offer 120p plus 0.2537 BSkyB shares for each Manchester United share. The deal values each Manchester United share at about 240p.
BSkyB's proposed takeover, which would make United the world's biggest club, will now be scrutinised by the Office of Fair Trading.
Former Manchester United manager Tommy Docherty admitted he was ``very disappointed'' but not surprised by the news that the board had accepted BSkyB's offer.
``I think Mr (Rupert) Murdoch has got Manchester United very, very cheaply,'' he said.
``There's an old saying that when Dick Turpin took your money he wore a mask and I think this is dreadful news for the true supporters of Manchester United and football in general.''
Furious Docherty accused chairman Martin Edwards of ``ignoring the supporters' wishes by rushing through the deal''.
``As a supporter of the club I feel like most supporters do - that Martin Edwards has sold out for the money. They were talking 48 hours ago that he would consider the supporters' feelings before he came to any decision. Obviously he has not done that at all.''
Docherty blasted United's prospective new owners for their lack of a football background.
``This (takeover) is bad for football. The people who are taking over the club are not football orientated - they don't know anything about football and they don't care about football. I don't think any of them has ever been to Old Trafford to see a football match.''
Docherty warned Edwards and his fellow board members to expect a backlash from fans who are strongly opposed to the takeover.
``This is a good deal for Rupert Murdoch and good luck to him. It is a bad thing in my opinion for the supporters of Manchester. I think we could see a big drop in attendances.''
Manchester United manager Alex Ferguson said: ``They (Sky) have done a fantastic job but some consideration must be given to those people in hospital and those who cannot afford it.
``Sky have created a profile for players. In the sixties it was Albert Finney, Richard Burton and Tom Courtney who were idols of the screen but they have been replaced by footballers.''
United shareholders' campaigner Michael Crick said he is unhappy by news of the BSkyB deal even though he can expect a £2,000 windfall.
``My problem is Rupert Murdoch isn't a Manchester United supporter,'' he said. ``He's never shown any interest in soccer.
``Perhaps I'm rather old-fashioned but I feel that football clubs should be run by people who support the team.
``It's the shareholders who are going to get the money. It's not as if it's going to be spent on players or facilities.
``The people who are going to benefit are the financial institutions and Martin Edwards, who stands to gain £85million.''
``It's very difficult for ordinary shareholders to do anything about this.
``I stand to make £2,000 but I don't want that. I want the club to remain in the hands of the people who support it,'' Crick told BBC Radio Five.
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