The announcement ends years of takeover speculation surrounding the indebted Italian club which is now poised to become the only Serie A side with foreign ownership, unlike the much courted English Premier League.
"Good things don't come easy," Di Benedetto told a news conference at a law firm in Boston. "I never felt that I would give up on the quest for this team."
The new consortium, which is 60 percent owned by DiBenedetto and 40 percent owned by Italian bank UniCredit, bought a 67 percent stake of Roma at an agreed price of 70.3 million euros.
Of that, 60.3 million relates to the purchase of shares at a price of 0.6781 euro each. The stake was bought from Italpetroli, which controlled Roma.
Under Italian law, the consortium would need to make a public offer to purchase the remaining 33 percent stake in the soccer club.
DiBenedetto, who has been a partner of New England Sports Ventures which owns the Boston Red Sox Major League Baseball team and English Premier League side Liverpool, wants to attract more local players to Roma.
"If you look around professional football today, there are a number of players who grew up in greater Rome," DiBenedetto said during a news conference held jointly with UniCredit chief operating officer Paolo Fiorientino.
"It's our goal to have more of them playing for AS Roma. I think we will put in place the people who will make it attractive for these young men to sign with us."
"Our hope and our objective is to be as successful in Rome as Mr. Berlusconi was with his team in Milan," DiBenedetto added, referring to AC Milan owner and Italian prime minister Silvio Berlusconi.
Cash-strapped Roma are now managed by former player Vincenzo Montella following coach Claudio Ranieri's resignation in February.
The Italian club lost to Shakhtar Donetsk in the Champions league last 16 last month and are sixth in Serie A, three points behind Udinese, having been runners-up last season.
Foreign investors had previously snubbed Serie A and instead were drawn to the more lucrative English Premier League where top stadiums are often full and merchandise sales significantly boost profits, unlike in Italy.
Liverpool, Manchester United, Aston Villa and Sunderland are all owned by Americans.
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