Bolatti, a member of Argentina's 2010 World Cup squad, links up with compatriots Andres D'Alessandro, Pablo Guinazu and Fernando Cavenaghi at the team based in the southern city of Porto Alegre.
"I wasn't getting the opportunity to play in Italy, which is why this chance Inter are giving me is so important," Bolatti told the club's website.
"I didn't need to give it much thought. This is a big (South) American club, and also close to Argentina. I'm very happy with this new challenge," said the former Porto player who shone for Huracan in the 2009 Argentine Clausura championship.
Midfielders D'Alessandro, South America's Player of the Year, and Guinazu helped Inter win the 2010 Libertadores Cup.
Bolatti and former River Plate striker Cavenaghi, who signed last week on loan from Girondins Bordeaux, have been recruited to try and help the Brazilian side retain their title.
Inter open the defence of the Libertadores Cup away to Emelec of Ecuador in Group Six on February 16.
They are presently taking part in the Gaucho (Rio Grande do Sul) championship, one of the many state competitions that open the season. The Brazilian championship starts in May.
