The shares rose to $35.89 (£24.87) before dropping back, as Murdoch made the comments following the release of the group's full-year and fourth-quarter results.
This morning in New York, the stock had been trading down 2.5% at $35.80 (£24.80) as it announced revenues of $13.8bn (£9.5bn), down from $14.2bn (£9.8bn) last time, while operating profit slid to $1.67bn (£1.1bn) from $1.73bn (£1.2bn) a year ago.
For the fourth quarter, News Corp reported operating profit of $145m (£100.6m), compared with $185m (£128.4m) last time.
News Corp has been in negotiations with GM about merging News Corp's digital division, BSkyB parent Sky Global Networks, with Hughes, the GM division which owns DirecTV.
However, last week Murdoch's bid looked to be in trouble when GM said it would consider a rival, hostile bid by DirecTV rival EchoStar.