MILAN (Reuters) - Italian Prime Minister Matteo Renzi said premiers should be limited to two terms in office, as he gears up for a referendum on constitutional reform that some fear could give excessive powers to the government and its leader.

Italy sets no limit on how many times someone can become prime minister, and critics say that the reform, which would drastically reduce the powers of the Senate and grant the lower house more, could create more conducive conditions for premiers to win an unlimited number of mandates.

"I think we should do at the most two mandates ... I would be ready to sign any law in this sense," Renzi said in a debate shown on Italian daily La Repubblica's online TV channel.

"Whoever governs, wears himself out ... that's enough of politics for life," Renzi said during the debate.

The 41-year-old, who came to power two years ago by ousting grand coalition-leader Enrico Letta, has staked his political future on winning the referendum which he says is crucial to more stable and stronger government.

In April, Italian lawmakers agreed constitutional reform to drastically reduce the powers of the Senate, granting relatively stronger authority to the lower house.

That is now being put to a popular vote in October.

While governments in Italy have historically changed before their terms were completed, frequently prompting economic problems, some politicians have repeatedly returned as premiers.

In the last three decades, Silvio Berlusconi was prime minister four times for three different governments.

Asked about Brexit, Renzi reiterated his belief that a vote to leave the European Union would be disastrous for Britain and would create financial turbulence in the very short term.

"In the mid- to long-term, however, I don't have an apocalyptic view. For Italy and Europe it won't be a tragedy," he said.

(Reporting by Stephen Jewkes; Editing by Louise Ireland)