MOSCOW, September 25 (RIA Novosti) - The launch of three Glonass navigation satellites has been moved back by at least a month due to a technical defect in one of the satellites, the head of the federal space agency said on Friday.

Roscosmos's Anatoly Perminov said he had not as yet been officially notified of the specific cause for the postponement of the launch, which had been scheduled for Friday from the Baikonur space center in Kazakhstan.

"I have to be sure that there will not be any problems with the satellites we are planning to orbit. I believe that a month should be enough for a working group to sort things out, and by the end of 2009, all six Glonass satellites will be launched," he said.

Glonass - the Global Navigation Satellite System - is the Russian equivalent of the U.S. Global Positioning System, or GPS, and is designed for both military and civilian uses. Both systems allow users to determine their positions to within a few meters.

The 18 satellites the system requires for continuous navigation services covering the entire territory of the Russian Federation are currently in orbit, and the six due to go up in two launches this year would bring numbers up to the 24 needed to provide services worldwide.

A total of 9.9 billion rubles ($360 million at the current exchange rate) was allocated for Glonass from the federal budget in 2007, and 4.7 billion rubles ($170 million) in 2006.

Prime Minister Vladimir Putin signed an order on September 12, 2008, providing an additional $2.6 billion to develop the system.