"These six domestic companies have been given 13 months to find appropriate locations to build new atomic power plants," the director of the agency's nuclear energy production department, Ahmad Fayaz Bakhsh, was quoted as saying.
"After finalising the locations, construction of the power plants can begin," he said, without mentioning how many would be built.
The announcement came with Iran facing a fourth set of UN sanctions over its refusal to freeze uranium enrichment, a process used to manufacture nuclear fuel but which can also be diverted to make the core of an atomic bomb.
Iran, OPEC's number two oil exporter, has vehemently denied Western allegations it is seeking to to build nuclear weapons and insists it only wants to produce energy for its growing population.
A Russian contractor is currently building Iran's first nuclear power plant in the southern city of Bushehr on the Gulf, but completion has been repeatedly delayed.
Gholam Reza Aghazadeh, the head of Iran's atomic agency, was quoted as saying last week that Bushehr was expected to start up by the end of the year.
Among the six chosen to look for nuclear sites is Khatam-ol-Anbia, the vast business arm of Iran's ideological Islamic Revolutionary Guards Corps, which is under US and EU sanctions for links with nuclear proliferation activities.
Fayaz Bakhsh said that four foreign companies — two Russian, one from Canada and a Swiss firm — had joined 58 domestic bidders for the contract.
Khatam-ol-Anbia is involved in major projects in Iran, including oil and gas developments, infrastructure such as ports, bridges and the Tehran metro, telecommunications and agricultural projects.
In October, the US administration slapped unilateral sanctions on the Guards and its elite Quds Force and blacklisted a host of government agencies, banks and individuals as it stepped up the pressure on Iran over its nuclear drive.
The EU also earlier this month introduced fresh sanctions after Tehran gave an ambigious response to an incentives package drawn up by six world powers to persuade Iran to halt enrichment.
Among the other companies chosen are engineering outfits linked to the energy ministry, an agriculture ministry venture and another private family company involved in oil and gas projects both at home and abroad.
In April 2007, Iran sought international bids to build two nuclear power stations alongside the unfinished Bushehr project.
The following month, it said it had started building a 360-megawatt nuclear power plant at Darkhoin on a river not far from the Iraqi border, using indigenous technology.
"Darkhoin is under basic design and there has been a nine-year scheme drafted for its construction," Fayaz Bakhsh was quoted as saying by state television on Tuesday.
