ROME — Roma president and Boston investor James Pallotta remains optimistic that construction will begin on a new stadium inspired by the Colosseum by the end of the year.
The project on Rome’s outskirts has been slowed by a long approval process involving city and regional authorities.
‘‘We’re still on the same timetable,’’ said Pallotta, chairman of Raptor Capital Management in Boston and a co-owner of the Boston Celtics. ‘‘Hopefully this fall. It should go through by then for putting shovels in the ground.’’
When Roma unveiled a model for the stadium at city hall a year ago, the plan was to have it open for the 2016-17 season.
‘‘It’s actually going pretty well. Everyone wants it — the mayor, the city council — it’s just an incredibly complex project,’’ Pallotta said following Roma’s 1-1 draw with Juventus on Monday.
‘‘It’s not complex because of the regulatory side of it. It’s just a complex project,’’ Pallotta said. ‘‘It’s not a football stadium that’s only for football. There’s an office park, there’s a training facility, there’s 300,000 square feet of live entertainment space. There’s going to be festivals and concerts and (American) college football games. So it’s a very, very complicated facility.’’
Labeled ‘‘Stadio della Roma’’ for now — until naming rights are awarded — the facility will seat 52,500 spectators and be able to expand to 60,000 for major matches.
‘‘We already had a number of college teams ask us a year ago about building a stadium,’’ Pallotta said. ‘‘And I would like to get the NFL sometime, too.’’
Pallotta met with Rome Mayor Ignazio Marino at city hall on Friday to discuss the project.
‘‘There’s a lot of optimism and a lot of certainty to begin seeing workers building the stadium by the end of 2015,’’ Marino said after the meeting.
Building costs for the stadium are estimated at 300 million euros ($335 million) but the overall price, including surrounding infrastructure and transport, will run beyond 1 billion euros ($1 billion).
With Rome bidding for the 2024 Olympics, the new stadium could also be used for soccer or other sports during the games if the capital is selected by the IOC.
The new stadium will be in the Tor di Valle area in the city’s southwest, about halfway between downtown and Fiumicino airport. It is located on the banks of the Tiber River, so there has also been some environmental opposition.
For years, Roma has shared the Stadio Olimpico with city rival Lazio but that stadium features a running track and poor sightlines for soccer. The Olimpico is controlled by the Italian Olympic Committee, while Roma will operate the new stadium.
The stadium has been a big goal since Roma was purchased by a four-man group of Boston executives who in 2011 became the first foreign majority owners of a Serie A club. It’s being designed by American architect Dan Meis, who has drawn up the plans for numerous stadiums and arenas in the United States, plus the Saitama Super Arena in Japan.
Andrew Dampf can be followed at www.twitter.com/asdampf