The deal was reached after six months of negotiations and will see Thohir own 70 percent of Inter Milan, La Repubblica said.
Thohir has been linked with a takeover of the Italian giants since last season when Inter finished in a disappointing ninth place and failed to qualify for European competition.
Following their dismal 2012-2013 season, Inter's value has dipped to an estimated €316 million, according to Forbes business group which rates it as the 14th most valuable club in the world.
Inter could now be in line for a cash injection that could boost their bid to build a new stadium and create a winning team which they can then market around the world.
Inter, the last Italian side to win the Champions League in 2010 when they won the treble under Jose Mourinho, are reported to be desperate for a move away from the San Siro ground they share with city rivals AC Milan.
But Moratti has previously said he wants the club to take advantage of ripe markets in Asia which English Premier League giants like Manchester United have exploited.
"As a club Inter needs to expand and break into new markets. And with Erick (on board) this would be possible," Moratti was quoted as saying on August 3rd.
Gazzetta's newspaper report claimed last month that Indonesia, which has the world's largest Muslim population, already boasted 11 million Inter fans.
Thohir will become the first Asian owner of a major Serie A club but he is no stranger to investing in major sports.
The son of Teddy Thohir, co-owner of the automotive group Astra International, the 43-year-old Thohir owns shares in basketball side, the Philadelphia 76ers, as well as being a majority shareholder in DC United, a Major League Soccer team.