“Avatar” director James Cameron gave a vote of confidence to Jim Gianopulos, who takes over as sole head of News Corp.’s Twentieth Century Fox film studio when co-chief Tom Rothman steps down at year-end.

Cameron, who is developing at least two sequels to “Avatar,” said in an e-mail his plans remained “rock solid.” The 3-D picture about a mining company’s treatment of an alien species in a distant world is the top-grossing movie in history, with $2.78 billion in worldwide ticket sales. Rothman said on Sept. 14 he would step down at the end of 2012.

The studio’s relationship with Cameron runs deeps. The first “Avatar” sequel is scheduled for release in 2015. The director is also developing two other movies at Fox, the science-fiction thrillers “Battle Angel” and “Fantastic Voyage.” Cameron’s past films with Los Angeles-based Fox include “Aliens” and “The Abyss.”

“I also have a fantastic working relationship with Jim Gianopulos, to say nothing of a friendship going back over two decades,” Cameron said. “So I know our footing with Fox on future ‘Avatar’ films will still be rock solid.”

The original “Avatar” surpassed Cameron’s “Titanic” to become the top-grossing movie of all time. “Titanic,” released in 1997 and distributed overseas by Fox, has taken in $2.19 billion globally, including ticket sales from a 3-D version released in April.

“Avatar” was estimated to generate as much as $1 billion in profit for News Corp. (NWSA) and its partners, people familiar with the matter said during the film’s 2009-2010 run in theaters.

‘Titanic’ International

Gianopulos, 60, who shared the role of chairman and chief executive officer of News Corp.’s film unit with Rothman for 11 years, has worked closely with Cameron as a Fox executive since the 1990s. He oversaw the international distribution of “Titanic,” which has accounted for $1.53 billion of the film’s total sales, according to Box Office Mojo, an industry researcher.

“That relationship was forged on ‘Titanic’ and Jim has always been the Cameron connection at the studio,” said Tom Sherak, who was the studio’s domestic distribution chief at the time.

Rothman was head of production for Fox while “Titanic” was being shot at a special facility in Mexico’s Baja California. They also worked together on “Avatar.”

“We forged a strong bond of mutual respect and creative partnership in that crucible of fire,” Cameron said of Rothman. “Our mutual love of film and filmmaking kept us friends and good partners, as did his great sense of humor.”

News Corp., based in New York, fell 0.5 percent to $24.48 at the close in New York. The Class A shares have gained 37 percent this year.

To contact the reporter on this story: Michael White in Los Angeles at mwhite8@bloomberg.net

To contact the editor responsible for this story: Anthony Palazzo at apalazzo@bloomberg.net