Rupert Murdoch telephoned AT&T Inc Chief Executive Randall Stephenson twice in the last six months and talked about cable network CNN, sources briefed on the matter told Reuters on Friday.
According to one of the sources, the 86-year-old executive chairman of Twenty-First Century Fox Inc offered to buy CNN in both conversations.
Another source said Murdoch had "zero interest" in owning CNN.
Representatives of Twenty-First Century Fox, AT&T and Time Warner, CNN's parent, declined comment.
CNN has become a sticking point in antitrust approval of AT&T's $US85.4 billion ($A119.6 billion) deal to buy Time Warner Inc, hatched in October 2016.
Justice Department staff have recommended that AT&T sell either its DirecTV unit or Time Warner's Turner Broadcasting unit - which includes CNN - a government official told Reuters on Thursday, in order to gain antitrust approval.
On Thursday Stephenson said he had no interest in selling CNN and that he was ready to defend the deal in court if necessary.
According to one of the sources on Friday, Murdoch called Stephenson twice, unprompted, on May 16 and August 8 and on both occasions asked if CNN was for sale. Stephenson replied both times that it was not, according to the source.
It would not be the first time Murdoch has attempted to take control of CNN.
Twenty-First Century Fox made an $US80 billion offer for Time Warner in 2014 but abandoned the plan in the face of Time Warner's resistance. At that time, Fox had planned to divest CNN - which competes with Fox News - in order to avoid antitrust issues.
There is no law against a company owning two cable networks, but there is a Federal Communications Commission prohibition on owning two broadcast networks. A Fox deal with CNN could face antitrust concerns because of the market share that a combined company would have among cable news viewers.
"I have been called and asked if I would sell CNN by numerous people," Stephenson told the New York Times DealBook conference on Thursday, but that selling CNN made no sense.
