Iran's first nuclear power plant at Bushehr has fed its first kilowatts of electricity into the national grid, the plant's constructor said.
The plant's unit, whose total capacity stands at 1000 MW, was launched late on Saturday at a capacity of 65 MW, said Russia's Atomstroyexport company.
Iranian President Mahmoud Ahmadinejad said in mid-August that the plant would go into full operation by the end of the year.
The fuel for Bushehr was provided by Russia, which completed the long-delayed construction of the plant last summer. The plant was expected to start operating in February.
Under a bilateral agreement, approved by the International Atomic Energy Agency, Russia will initially operate the plant, supplying its fuel and taking away all the spent fuel for the next two or three years, but will eventually hand over full control to Iran.
