LONDON — News Corp. chief Rupert Murdoch said today that he panicked when he closed the News of the World tabloid last year, one of a series of revealing exchanges made at an inquiry into British media ethics.

The 81-year-old media magnate acknowledged that the telephone hacking scandal which erupted last July at the Sunday tabloid was a “serious blot” on his reputation, but claimed his company was drawing a line under the sordid episode.

“I’ve spent hundreds of millions of dollars” cleaning up News Corp. subsidiary News International, Murdoch told the inquiry. “We are now a new company altogether.”

Murdoch’s was testifying for a second day at an inquiry run by Lord Justice Brian Leveson, a hotly anticipated appearance which has so far seen the media mogul meet pointed questions about his nexus of political influence and business interests with a wall of denials.

Murdoch largely stuck to the same script today, but a few new revelations tumbled out — along with a strikingly personal admission that he didn’t do enough to nip the scandal in the bud.

“I failed,” Murdoch said at one point. “And I’m sorry about it.”

Pressed on why he closed the News of the World at the height of the scandal, Murdoch said it was an impulse move.

“I panicked,” Murdoch said. “But I’m glad I did.”