Russia's space agency threw in the towel today on the aging space station Mir, saying that additional financing could not be found for the world's longest-orbiting manned space vehicle and that it will be mothballed in anticipation of its demise early next year.

The announcement was a defeat for Energia, the Russian company that operates Mir, the crown jewel of Russia's space program, and followed an unsuccessful search for private financing. The most recent potential benefactor, British businessman Peter Llewellyn, 51, who created an investment company with Russian officials to raise cash to keep Mir aloft, pulled out of the plan last week.

"All the attempts to find big money did not meet with success so far," said Energia spokesman Sergei Gorbunov.

A panel of Russian space designers decided that Mir's current three-man crew will be the last and will come down in August, when government money expires, although funding by the cash-strapped Russian government has already slowed to a trickle.

"This utterly discouraging decision is dictated by the economic crisis in the country and absence of Western investors," flight director Vladimir Solovyov told Mir's current crew today. "There is no uncertainty. The plans to leave behind one man, the commander or engineer, must be forgotten. The crew will land as planned on August 23rd."

On July 10, an unmanned cargo vessel will ferry new equipment to Mir so controllers on the ground can maneuver it after the crew leaves. The station is cruising at an altitude of 223 miles and will have to be drawn into Earth's gravitational pull so it can burn up in the atmosphere. While mothballed, Mir will be maintained in orbit by its own engines; early next year, when a final decision to ditch it is made, a refueling vehicle will dock with Mir and its engines will be used to take the station out of orbit, according to the Interfax news agency.

The decision to abandon Mir will likely be greeted with relief at NASA, which has been concerned that continued operation of the orbiter would sap Russian resources from construction of the international space station, now underway. U.S. officials feared that space vehicles, resupply ships and boosters needed for the new station would be used to keep Mir alive.

CAPTION: Flight director Vladimir Solovyov called the decision to abandon Mir "utterly discouraging" and said it was dictated by Russia's economic crisis.