Searchers for aviator Steve Fossett may not be giving up, but his good friend Richard Branson is. Branson announced on NBC's Today show that "chances are that he's no longer with us."

Last week, the search for Fossett turned from the air to the ground. But, the ground search has been stalled. Fossett disappeared in early September in a single-engine plane. Branson also said that Fossett's wife was starting to attempt the fate that he's likely gone.

"I think the chances are that he's no longer with us," Branson said. "I think everybody involved has pretty well given up hope, sadly."

Branson said Fossett's wife, Peggy, had written to him to say she was returning to Nevada for one final search but the likely fate of her husband was "beginning to sink in."

Fossett had previously survived a nearly 30,000-foot plunge in a crippled balloon and a dangerous swim through the frigid English Channel.

Branson paid tribute to Fossett's record-breaking prowess. He said Fossett had set 125 world records since the age of 55

"Incredible individual," Branson said.

Fossett, who made millions as a commodities broker in Chicago, also completed the 1,165-mile Iditarod sled-dog race, scaled some of the world's best-known peaks, sailed and flew around the world, and set more than 100 aviation and distance records.