Carl Icahn, the financier, today disclosed that he and a group of investors will press Time Warner to shed its cable TV unit and embark on an aggressive buyback of $20 billion (£11bn) of its own shares.

Mr Icahn, who is known for taking stakes in companies and agitating for strategic changes, said he and several other investors have amassed more than 120 million shares of Time Warner, or about 2.6 per cent of the giant media conglomerate, which owns CNN and is behind Time magazine and the Harry Potter films.

Earlier this month Time Warner said it planned to repurchase $3 billion of its own shares over the next two years in a bid to raise the company’s sagging stock price. However, Mr Icahn and his partners believe Time Warner can afford much more dramatic steps to boost shares.

Mr Icahn said in a statement that while he felt Time Warner has done a "commendable job" managing each of its businesses and announced steps to increase shareholder value, "it has not moved quickly enough and it has not proposed measures which would enhance values to the degree necessary to realize the inherent value" of its assets.

He added that he believed the separation of the cable unit as well as an immediate repurchase of $20 billion in Time Warner shares would push up the price of the stock to a level that reflected its fair value.

Mr Icahn said he had contacted Time Warner’s chief executive, Dick Parsons, and planned to meet with him this week to discuss his views.

"Our board and our management are committed to creating long-term value for all shareholders, and we have been on a course that demonstrates that commitment," a Time Warner spokesman said.

Time Warner has already said it intends to spin off part of its cable company to shareholders as part of a three-way deal with Comcast, the leading cable company, to acquire the assets of the bankrupt cable provider Adelphia Communications.

Earlier this month, Time Warner agreed to pay at least $2.4 billion (£1.3 billion) to settle class-action lawsuits that accused the American media conglomerate of overstating its financial performance through use of sham transactions and improper accounting practices.

However, the company moved to soften the blow by unveiling plans for a $5 billion share buyback over the next two years. Wall Street investors have been unhappy with the group’s lagging valuation.

Shares of Time Warner rose 17 cents to $18.41 in morning trading on the New York Stock Exchange.

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