London (CNN) -- Rupert Murdoch admitted Thursday there had been a "cover-up" of phone hacking at his flagship British tabloid newspaper and apologized for not paying more attention to a scandal that has convulsed his media empire and rocked the British political establishment.
And he said that he had shut down the best-selling News of the World out of "panic" in the face of public fury about the revelation that a murdered teenage girl had been a victim of phone hacking.
Murdoch, who owns the Sun and the Times in London, as well as controlling the Wall Street Journal, New York Post and Fox News, said his News Corp. had been a victim of the cover-up, not the perpetrator.
"Someone took charge of a cover-up, which we were victim to and I regret," he said at the Leveson Inquiry, an independent British probe prompted by charges of illegal eavesdropping by his newspaper.
He blamed "one or two very strong individuals" at the paper, but did not name them.
"I also have to say that I failed," he said of the fact that he did not pay enough attention to the problem of phone hacking. He then paused a long time before finally continuing: "And I am very sorry for it."
If he had known the depth of the problem in 2007, when a private investigator and a Murdoch journalist were sent to prison for phone hacking, he "would have torn the place apart and we wouldn't be here today. But that's hindsight," he said.
The hacking scandal has led to dozens of arrests, two parliamentary investigations and the Leveson Inquiry, a judge-led independent probe set up by the British government.
Murdoch suggested key parts of the scandal have been overblown.
"The hacking scandal was not a great national thing until the Milly Dowler disclosure, half of which has been somewhat disowned by the police," Murdoch said.
He was referring to the revelation that people working for him had hacked into the voice mail of a missing 13-year-old who later turned out to have been murdered.
The Guardian newspaper originally reported that the hackers had also deleted some of her voice mails, leading to false hopes that she was still alive and deleting them herself. In fact, the messages may have expired automatically.
Murdoch Thursday described the atmosphere when news of the Milly Dowler hacking became public in July 2011.
"You could feel the blast coming in the window. I can say it succinctly. I panicked. And I am sorry I did," he said of his decision to close the tabloid. He later said he should have closed it years earlier.
"This whole business is a serious blot on my reputation," he said.
Murdoch was also grilled over his media empire's back-channel lobbying of the British government, and said he learned of the existence of one of the key lobbyists only "a few months ago."
Murdoch said he was "surprised" at the extent of the contact by the employee, Fred Michel, with the British government as it considered a bid by News Corp. to take full ownership of British Sky Broadcasting.
That bid that collapsed because of the phone-hacking scandal.
"You call it lobbying, I call it seeking of information," Murdoch told the Leveson Inquiry. "I didn't see anything wrong with his activities. I was I surprised that it had gone on so long, that there were so many e-mails, yes."
A government aide quit Wednesday over the revelation of the extent of the contacts, and there have been calls for the resignation of Culture Secretary Jeremy Hunt, who is named in the correspondence.
Murdoch spent hours Wednesday downplaying his political influence, even as British Prime Minister David Cameron said politicians had been too close to Murdoch over the years and the government aide, Adam Smith, resigned over communications between the culture ministry and News Corp.
Murdoch insisted Wednesday that he had "never asked a prime minister for anything" as he chronicled his personal relationships with prime ministers going back to Margaret Thatcher in the early 1980s.
The media baron also denied using the power of his press for personal gain.
At the same time, Cameron was saying politicians from across the political spectrum had been too close to Murdoch.
"I think we all, on both sides of this house, did a bit too much cozying up to Mr. Murdoch," he told the House of Commons as his government was battered over testimony Murdoch's son had given to the Leveson Inquiry the day before.
James Murdoch testified Tuesday that before Cameron became prime minister, he had met the politician over drinks at a pub and told him the company's Sun newspaper would support his Conservative party in the next election.
The younger Murdoch insisted that he knew little about the scale of phone hacking by people working for the News of the World, as he continued his fight to limit the damage the scandal does to him and his family's media empire.
The scandal has forced News Corp. to pay hundreds of thousands of pounds in compensation to the victims of phone hacking.
James and Rupert Murdoch have been hammered over the past year about what they knew about phone hacking by people working for them.
They have always denied knowing about the scale of the practice, which police say could have affected thousands of people, ranging from celebrities and politicians to crime victims and war veterans.
CNN's Dan Rivers, Erin McLaughlin, Elaine Ly and Claudia Rebaza contributed to this report.