It said the damage was probably caused by a short circuit while the craft was left abandoned for several months, and would explain why one of its solar panels was not functoning.

The current mission is the first to be privately funded. Mir was left abandoned last August because of shortage of money then drafted back into service. The present crew has been aboard since last month.

Sergei Zalyotin and Alexander Kaleri walked for more than five hours in space, returning safely to the station, the space flight mission control centre near here said.

Mir's basic module has been in earth orbit for the past 14 years.

Despite the success of the mission Mircorp, the company looking after the station's finances, is still seeing funds to finance the next planned mission in September.

"Mircorp remains confident of being able to put together the funds required for the expedition in September," spokesman Jeffrey Lenorovitz told AFP on Friday.

He said he was impressed by the station's performance. "Our Russian partners are doing everything on the dot," he said. "That's very important for our investors."

Two cargo vessels had been sent to Mir in February and April on schedule, and the cosmonauts had also successfully plugged an air escape which occurred last spring, causing pressure inside the vessel to drop gradually.

During their Friday stroll, the two cosmonauts practised using a special glue to plug holes on a panel similar to those covering the craft.

The operators say Mir has another two to three years' life in it. Mircorp says negotiations are in progress with potential investors. "A further expedition would enable us to instal an Internet portal in orbit for the first time in the history of space conquest," said Lenorovitz.

Mircorp intends putting information from Mir on the Internet, including meteorpoligical data and cosmonauts' reports.

The company also aims to set up a space tourism project in which those who can afford it would be allowed to spend a week aboard Mir -- for 30 million dollars.

Despite Mircorp's optimism, the Russian space agency expressed doubts last month about Mir's future. Its chief Yuri Koptev said the station might have to be destroyed in October if funds to ensure its future are not forthcoming.

Meanwhile, the space agency has its own grandiose ambitions for Mir. It hopes to revive a project to launch a Russian film star into space to shoot a movie aboard Mir.

"A very well known American producer whose name I can't divulge for the moment will be in Russia in June for negotiations on sending the actor Vladimir Steklov to Mir," said space agency spokesman Sergei Gorbunov.

Meanwhile, cosmonauts Zalyotin and and Kaleri were keeping the place ready Friday before returning to earth on June 2, after which Mir will go on automatic pilot again.