Italy must offer long-term support measures for nuclear power to make a comeback in the country in order to protect investments and offer a satisfactory regulatory framework, a top government official said Tuesday.

"We must think of support systems for nuclear that provide long-term rules and certainties," Guido Bortoni, head of the energy department at the industry ministry, said at a conference in Rome. He added this doesn't necessarily mean monetary incentives.

The center-right government announced in 2008 that it would introduce legislation to allow nuclear power to return to Italy, two decades after the public voted in a referendum to ban it. At the beginning of November the cabinet approved members of the governing committee of the new nuclear safety agency.

However, for the nuclear agency to be fully operational it needs to select its technical staff, Energy Undersecretary Stefano Saglia told reporters on the sidelines of the same conference.

The new agency must determine the specifics that allow companies interested in building nuclear plants to select suitable sites. Saglia didn't say when this was likely to happen.

"All you need is the agency," said Francesco Giorgianni, head of Enel's institutional affairs, at the same Rome conference. He added the process was at a "very important" phase.

The government aims to ultimately have a quarter of the country's electricity generated from nuclear, with another 25% coming from renewables. The remaining amount will come from fossil fuels. However, Saglia couldn't say when this target is expected to be met.

Enel has joined forces with nuclear behemoth Electricite de France SA (EDF.FR) to build up to four nuclear facilities in the peninsula with a combined capacity of about 6,400 megawatts for a total investment of between EUR16 billion and EUR18 billion.

The equally-split Enel-EDF venture plans to build about half of the Italian government's atomic target, with the first site scheduled to be operational by 2020.

Enel Chief Executive Fulvio Conti has asked for guarantees that the next governments won't scrap the nuclear program, allowing it to undertake the necessary investments.

Tuesday, Undersecretary Saglia said that although Italy needs to change its policy of "running on gas" to take into account nuclear and renewables in its energy strategy, he acknowledged that natural gas will dominate the country's energy scene for the next 20 years.

The industry and environment ministries plan to present to the government in 2011 a national energy plan, said Bortoni. It would be the first such plan in Italy since 1988.