Nassau County Executive Edward Mangano, developer Bruce Ratner and executives from the Barclays Center in Brooklyn broke ground on the renovation of the Nassau Veterans Memorial Coliseum with a swing of a sledgehammer Thursday.

Mangano smashed a hole in a wall of the main concourse of the arena to mark the start of the $260 million renovation project.

"We're glad to bring this vision to reality," Mangano said. "With this seed of growth, many new announcements are coming in the future. It's been a long road, but a road that will bring us a world-class Coliseum and we should all cheer for that."

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The yearlong project will result in a downsized arena of 13,000 seats and an adjacent entertainment center with up to seven restaurants, a movie theater, nightclub and retail.

The groundbreaking came a week after Mikhail Prokhorov, owner of the Brooklyn Nets basketball team, announced he had purchased a majority stake in the company that is redeveloping the Coliseum and building the entertainment complex.

Prokhorov's Onexim Sports and Entertainment, based in Moscow, will assume 85 percent ownership of Nassau Events Center, the entity created by Ratner to run the arena. Ratner, executive chairman of Forest City Ratner Companies, will retain 15 percent ownership of the development company.

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Officials say Onexim will maintain Ratner's vision for the property and will abide by the terms of the lease agreement with the county. That deal calls for Nassau Events to pay the county more than $500 million in rent and sales taxes over the course of the 34-year lease.

Irina Pavlova, president of Onexim Sports and Entertainment Holding USA, said Onexim and Ratner are full partners in the redevelopment.

"We believe in this thing 100 percent," Pavlova said.

Brett Yormark, CEO of Barclays Center and the Nets, said the refurbished arena will reopen in December 2016 with a concert featuring a "world class artist," and later will host an "iconic artist that played here in the past."

The arena will feature major entertainment acts along with minor league hockey, college basketball, professional boxing, concerts and other family entertainment. Also, the NBA Brooklyn Nets plan to bring their minor league team to the Coliseum for the 2017-18 season.

Representatives from World Wrestling Entertainment who attended the groundbreaking said they also had plans to bring shows to the Coliseum.

Yormark said Thursday that Barclays, which Ratner developed, has an agreement in principle with a Long Island company to purchase naming rights to the plaza surrounding the Coliseum. Officials have said they would keep the name of the Nassau Veterans Memorial Coliseum.