The Arabsat 4A telecommunications satellite owned by the Saudi ARABSAT company was launched from the Baikonur cosmodrome in Kazakhstan atop a Proton-M booster rocket equipped with an additional Briz-M upper stage, the Russian Federal Space Agency said in a statement.

The Proton-M successfully delivered the satellite to a preliminary orbit, but the Briz-M then failed on Wednesday to function properly and could not deliver the satellite to a designated orbit, the agency said.

An emergency panel of space officials was investigating the incident, it said.

Vyacheslav Davidenko, a Federal Space Agency spokesman, told The Associated Press that experts from the European Astrium company that had built the satellite were trying to save it by guiding it to a proper orbit using the vehicle own orientation engines.

He said: "Chances for success are slim."

Davidenko said that the satellite separated from the Briz-M earlier than required and remained in an orbit much lower than the designated one.

Series of mishaps

The bungled launch was the latest in a series of mishaps that have recently plagued Russia's space programme, jeopardising its hopes to earn more revenue from commercial launches of foreign satellites.

In October, a high-profile European satellite was lost because of a Russian booster failure. The loss of the $142 million CryoSat satellite dealt a major blow to the European Space Agency, which had hoped to conduct a three-year mapping of polar ice caps and provide more reliable data for the study of global warming.

Also that month, space experts failed to recover an experimental space vehicle after its return, engineers lost contact with an earlier launched Russian Earth-monitoring satellite and a new optical research satellite was lost due to a booster failure.

Following the failed launches, Vladimir Putin, Russia's president, fired the chief of the Khrunichev company that built the Rokot booster. The rocket that failed on Wednesday was also built by Khrunichev.