Iran's first nuclear power plant will begin supplying energy in early 2011, a senior official said, signalling a delay of several months after the spread of a global computer virus believed to have affected mainly Iran.

Iranian officials said on Sunday the Stuxnet virus had hit staff computers at the Bushehr plant, a symbol of Iran's growing geopolitical sway and rejection of international efforts to curb its nuclear activity, but not affected major systems there.
   
When Iran began loading fuel into Bushehr in August, officials said it would take two to three months for the plant to start producing electricity and that it would generate 1,000 megawatts, about 2.5 percent of the country's power usage.

"We hope that the fuel will be transferred to the core of the Bushehr nuclear power plant next week and before the second half of the Iranian month of Mehr (Oct 7)," Ali Akbar Salehi, head of Iran's Atomic Energy Organisation, was quoted on Wednesday as saying by the semi-official news agency ISNA.    

"The ground is being prepared in this regard and, God willing, the fuel will be loaded to the core of the reactor completely by early November and the heart of Bushehr power plant will start beating by then."    

Salehi added: "Two to three months after that electricity will be added to the networks." This would mean Bushehr generating electricity from January or February.    

Security experts say the Stuxnet computer worm may have been a state-sponsored attack on Iran's nuclear programme and have originated in the United States or Israel, the Islamic Republic's arch-adversaries.

Iran's programme includes uranium enrichment -- separate from Bushehr -- that Western leaders suspect is geared towards developing atomic bombs. Iran says it is refining uranium only for a future network of nuclear power plants.   

Diplomats and security sources say Western governments and Israel view sabotage as one way of slowing Iran's nuclear work.
   
Little information is available on how much damage, if any, Iran's nuclear and wider infrastructure has suffered from Stuxnet and Tehran will probably never disclose full details.   

Some analysts believe Iran may be suffering wider sabotage aimed at slowing its nuclear advances, pointing to a series of unexplained technical glitches that have cut the number of working centrifuge machines at the Natanz enrichment plant.
   
Bushehr was begun by Germany's Siemens in the 1970s, before Iran's Islamic Revolution, but has been dogged by delays. Russia designed and built the plant and will supply the fuel.

To ease nuclear proliferation concerns, it will take back spent fuel rods that could otherwise be used to make weapons-grade plutonium. Bushehr is also being monitored by inspectors of the UN nuclear watchdog.   

Washington has criticised Moscow for pushing ahead with Bushehr despite Iranian defiance over its nuclear programme. - Reuters