Italy's reformist premier Matteo on Monday welcomed the privatisation of Poste Italiane - the country's biggest sell-off since the 1990s - calling it a "change of direction".
"A company that a decade ago was the most beholden to politics and interest groups, must now answer to shareholders and the market," Renzi wrote on Facebook.
"This too is a change of direction," he said.
A share offering will see up to 38.2 percent of the group, which also has major banking, mobile telephone and logistics activities, offered to retail and institutional investors and the company's 143,000 employees.
Founded in 1862, Poste Italiane currently has annual sales of 28.5 billion euros and 32 million customers.
At the presentation of the IPO on Monday, Poste Italiane's CEO Francesco Caio said the privatisation "certainly has financial and economic importance, but also has an industrial policy importance and will contribute to the modernisation of the country".
He said he anticipated strong interest from international investors.
The postal service would be reviewed in two years' time, Caio said.
Trading in the new shares is to begin in the week starting 26 October with the government looking to raise up to 3.7 billion euros from a move it has presented as symbolic of its broader economic reform agenda.
The capital raised from the privatisation of the postal service will make only a small dent in Italy's 2.2 trillion euro debt mountain, but Renzi sees it as the first step in a bigger privatisation programme.
Stock market launches for air traffic controller Enav and Italian state railways (FS) are expected to follow Poste Italiane's.
Renzi hopes the privatisations will help attract foreign investors to a country that is slowly emerging from recession.
