Atlanta added a lowlight to its sports record book Tuesday, becoming the first city in the NHL’s modern era to lose two teams.

Thirty-one years after the Flames left Atlanta for Calgary, an agreement was reached to sell the Thrashers to a Canadian group that will move the team to Winnipeg. The Flames lasted eight seasons in Atlanta. The Thrashers made it through 11.

The Atlanta Spirit ownership group’s deal to sell the Thrashers to True North Sports and Entertainment requires the ratification of the NHL Board of Governors, which meets June 21 in New York. A 75-percent vote is required to approve a franchise sale, and a majority vote is needed to approve relocation. Board approval is considered little more than a formality, though, since the transaction has the blessing of NHL commissioner Gary Bettman.

Bettman was in Winnipeg on Tuesday for a news conference announcing the deal, which was negotiated with his consent over the past 2 1/2 weeks.

“As we have said repeatedly, we don’t like to move franchises,” Bettman said Tuesday. “But sometimes, we simply have no choice.”

He considered this to be such a case because of Atlanta Spirit’s unwillingness to continue funding the Thrashers’ operating losses — pegged in court documents at roughly $20 million per year — and inability to find a buyer who would keep the team in Atlanta amid such losses.

“No real local purchaser emerged, and ultimately Atlanta’s ownership, which has made it clear they want out, reached outside the Atlanta market,” Bettman said.

“To our fans in Atlanta, we are not happy about leaving Atlanta,” Bettman added. “Please be assured it was never about whether Winnipeg is better than Atlanta. The decision to come to Winnipeg was made only after Atlanta’s ownership made the decision that they were going to sell, even if it meant that the club was going to leave Atlanta.”

Michael Gearon Jr., one of the Thrashers’ owners, choked up several times as he discussed the situation Tuesday.

“You get in a situation where you are faced with no other options, and that’s where we are,” he said. “It’s emotional. It’s painful. It’s saddening.”

Said Thrashers president Don Waddell, who has been with the franchise since its inception: “It is one of my tougher days. ... Obviously, being here from Day 1, to start a franchise and to see it leave, ‘disappointed’ is an understatement.”

The NHL leaves a metro area of more than 5 million people — the United States’ eighth largest TV market — for a city of 700,000 in hockey-loving Canada. The league returns to a city it left in 1996, when the Winnipeg Jets moved to Phoenix and became the Coyotes.

The True North group set its sights on the Thrashers after the city of Glendale, Ariz., agreed three weeks ago to cover another $25 million in Coyotes losses to prevent that team from moving back to Winnipeg.

The Thrashers, who entered the NHL as an expansion team in 1999, struggled on and off the ice for most of their time in Atlanta. They reached the playoffs only once (2007), never won a postseason game and ranked in the league’s bottom four in attendance each of the past three seasons. The owners say the team has lost $130 million since 2005, including $20 million in the lone playoff season.

True North is believed to be paying $170 million for the franchise — $110 million to the Spirit and $60 million to the league as a relocation fee.

Lawyers worked through the night Monday on the transaction, including a 4:30 a.m. conference call with Bettman, with the last piece of the complex deal put in place at mid-morning Tuesday.

The relocation will mean job losses for an unknown number of Thrashers employees, although Waddell said he hopes some staffers will accompany the team to Winnipeg and others will fill openings on Atlanta Spirit’s other properties, the Hawks and Philips Arena.

Waddell said he won’t remain with the soon-to-be-renamed team after the sale closes and isn’t sure of his next career move.

As to whether Atlanta might someday get a third NHL franchise, Waddell said: “That’s a good question. I don’t really know the answer to it. ... Never is a long time, so I wouldn’t want to say that. Obviously, in the short term, it’s not going to happen.”