The broadcaster confirmed it that the trio had recently expressed interest in acquiring a controlling stake and distributing cash to shareholders as well as taking on "a very material increase in ITV's level of debt".
The board, chaired by Sir Peter Burt, said the proposal was not in the best interests of all shareholders, and issued this statement:
"The board carefully examined this proposal in the context of the company's own strategic plans and was concerned that, inter alia, shareholders who did not wish to retain their shares in this highly leveraged structure would not have been assured of receiving a cash price for their shares at an appropriate premium to reflect the change of control envisaged by the proposal."
The approach was reported by The Daily Telegraph, which did not mention Blackstone's role.
It stops short of a complete takeover of ITV, which was yesterday valued at around £4.4bn.
The suitors are proposing to buy a £1.5bn controlling equity stake, leaving other shareholders the opportunity to stay invested in ITV, which is confronting falling ad revenues at its main channel ITV1 but expanding into digital services. They would then borrow heavily to refinance ITV and return money to investors.
ITV's share price climbed around 9% earlier this morning to touch 128p compared with yesterday's closing price of 117p. After ITV issued its statement at 9.30am, the price went up from 125p to 128p.
According to the Telegraph, ITV is likely to come under pressure from major shareholders, including UBS, Fidelity and Brandes, to consider the approach seriously.
The move raises the prospect of a return to television for Greg Dyke, who has been out of the industry since his resignation as BBC director-general in January 2004 after the Hutton Report criticised the corporation's journalistic standards over the allegations it made that the government overstated the case that Iraq possessed weapons of mass destruction.
Dyke joined Apax as an adviser in October 2004, leading to continuing speculation he would return to ITV. He was at one stage managing director of LWT, until the company fell victim to a hostile takeover by Granada in 1994.
Charles Allen, ITV's chief executive and formerly Granada chief executive, is not believed to be keen to work with Dyke.
A number of private equity houses and media companies have previously been linked to ITV, including last summer a consortium of Goldman Sachs, Apax and Time Warner.
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