RENO, Nev. — Teams searched rugged terrain yesterday for a plane carrying aviation adventurer Steve Fossett, the first person to circle the world solo in a balloon, but crews had little idea where the plane might be, federal officials said.

Mr. Fossett took off in the single engine Bellanca at 8:45 a.m. Monday at a private airstrip in western Nevada and didn’t return as scheduled. A friend reported him missing, said Ian Gregor, a Federal Aviation Administration spokesman in Maryland.

“The Civil Air Patrol is looking for him. One problem is he doesn’t appear to have filed a flight plan,” Mr. Gregor said. “They are working on some leads, but they don’t know where he is right now,” Mr. Gregor said.

The search for the millionaire entrepreneur was being coordinated by the Air Force’s Rescue Coordination Center in Langley, Va., Mr. Gregor said. The Nevada Division of Emergency Management and the Nevada Highway Patrol were assisting.

Mr. Fossett, of Beaver Creek, Colo., took off from an airstrip at hotelman Barron Hilton’s Flying M Ranch, about 70 miles southeast of Reno in the south end of the Smith Valley, Trooper Chuck Allen said.

“They don’t know exactly where he was going,” Mr. Allen said.

A telephone message left for a Peggy Fossett in Beaver Creek was not immediately returned.