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Executive producers Judd Apatow and Jenni Konner, and creator, executive producer and cast member Lena Dunham talk about HBO’s “Girls.” Reuters/Lucy Nicholson

In the wake of Rupert Murdoch’s failed takeover bid for Time Warner Inc. (NYSE:TWX) last week, speculation is running rampant about the media company’s key properties and what they are actually worth.

The New York Post’s Richard Morgan on Thursday cited anonymous sources who said Time Warner’s most prized possession, HBO, could eventually see its own initial public offering, or at least a market valuation to showcase its worth to shareholders. The network behind some of the buzziest television shows around -- including “Game of Thrones,” "True Blood," “Girls” and “True Detective,” not to mention admired predecessors like "The Sopranos" and "The Wire" -- generated $4.9 billion in revenue last year, about 27 percent of Time Warner’s total revenue, as the Wall Street Journal reported.

The company’s other divisions include Turner Broadcasting -- which includes CNN and TBS, among other networks -- and Warner Bros. Studios. As a whole, Time Warner is a much leaner company than it once was. Earlier this year, it spun off Time Inc. (NYSE:TIME), its less profitable print magazine empire, and it shed its pay-TV division, Time Warner Cable Inc. (NYSE:TWC), in 2009.

The Post reports that the HBO IPO idea was in the works before Murdoch, chief executive of Twenty-First Century Fox (NASDAQ:FOXA) and chairman of News Corp. (NASDAQ:NWSA), which owns the New York Post and Wall Street Journal among much else, proposed an $80 billion takeover bid in June. HBO, a premium-content producer and worthy foil for Netflix Inc. (NASDAQ:NFLX), is thought to be the main asset Murdoch was after. Unfortunately for Murdoch, the bid may have come up short: The Post estimates that HBO alone could be worth $118 billion.

The takeover bid has also sparked conjecture about the standalone value of CNN, which in the event of a Time Warner-21st Century Fox merger would likely have to be spun off to avoid antitrust concerns. (Murdoch’s company already owns CNN’s main competitor, Fox News.) Media analysts have estimated CNN’s value to be around $4.3 billion when adjusted for taxes, as the Los Angeles Times reported last week.

Even some entertainers are getting in on the speculation. On “The Daily Show” Tuesday night, host Jon Stewart launched a mock Kickstarter campaign to acquire CNN for himself -- currently viewable at the website LetsBuyCNN.com. Stewart set the fundraising “goal” at $10 billion and is offering some intriguing phony rewards. Backers who pledge $1 billion or more get to host a "Hunger Games" fight with the CNN anchor of their choice. (Ah, If only it weren’t a joke.)

Shares of Time Warner were down 0.25 percent at $84.01 on Thursday in after-hours trading.

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