Sun Country Airlines — the little vacation carrier formed by some Minnesota pilots and flight attendants 35 years ago and later owned by two of the state’s wealthiest families — is now owned by one of the nation’s most prominent investment firms.

Apollo Global Management, a New York-based firm led by investor Leon Black, on Thursday bought Sun Country from Mitch and Marty Davis, the Twin Cities billionaires who have owned it since 2011. Terms were not disclosed.

Sun Country will stay based in Eagan and continue to be led by Jude Bricker, a former Allegiant Air executive whom the Davis brothers hired as chief executive in July.

But the company’s future depends in doing in other cities what it does at Minneapolis-St. Paul International Airport: providing low-cost flights to vacation spots and other places that don’t support the frequency of service that bigger airlines prefer.

Mike Boyd, a Denver-based aviation consultant, said the deal is a validation by a prominent investment firm of the direction that Sun Country and other low-cost carriers have been moving for several years. Instead of trying to duplicate the sprawling networks of carriers like Delta, American and Southwest, Sun Country and airlines like Frontier, Spirit and Allegiant are creating demand for air travel where it didn’t previously exist.

“These airlines offer very low fares to get people to travel when they wouldn’t have otherwise,” Boyd said. “Instead of spending those discretionary dollars on something for the house, it’s ‘Hey, we’ll go to Tucson this weekend.’ ”

In the process, Sun Country and similar carriers formed a different layer to the airline industry. “What Leon Black and Apollo saw in this is a huge opportunity for them, a great platform to build on and get into this parallel airline universe,” Boyd said.

A smaller investment firm bought Frontier in 2013. Spirit and Allegiant are publicly held.

Apollo, a publicly traded firm that has owned or been a major investor in dozens of companies, has a substantial track record in travel and leisure, but the Sun Country deal marks its first purchase of an airline. It has held stakes in travel companies like Diamond Resorts, Great Wolf Lodge, Caesars Entertainment and Norwegian Cruise Line. In July, Apollo raised $24.6 billion for a buyout fund, the largest amount ever gathered by an investment firm.

“Sun Country presents compelling opportunities for innovation, efficiency and growth,” Antoine Munfakh, an Apollo partner, said. “Underpinned by a solid foundation of assets and people, including an outstanding team of executives and talented flight crews, we believe Sun Country has a very bright future.”

Marty Davis, the airline’s chairman, said Apollo has the money and people who can devote the time and energy needed to make Sun Country grow. “Airlines are an all-in thing,” he said. “I think it’s an opportunity to really become a big player in U.S. air travel.”

The Davis brothers also own Cambria, Davis Family Dairies and Cambria Mortgage and Title. They bought Sun Country out of the bankruptcy reorganization it was thrust into when its previous owner, billionaire Tom Petters of Minnetonka, liquidated his assets after being charged in the biggest business fraud in Minnesota history. He was later convicted.

Sun Country was formed in 1983 by former Twin Cities-based pilots and flight attendants of Braniff International Airways, which closed in 1982. For many years, it focused on charter service and flights for group tours created by travel agencies. In 1999, then owned by a Milwaukee travel agency firm, Sun Country transformed into an airline providing scheduled flights from MSP and Milwaukee. But after the Sept. 11, 2001, attacks created a travel recession, Sun Country tumbled into bankruptcy for the first time and closed.

A new firm led by former executives and some local investors revived the Sun Country brand in 2003 and aligned the revived airline with Hobbit Travel and Nevada casino owner Don Laughlin. Petters put together a group of investors to buy the company in 2006.

The Davis brothers stabilized the airline and built up its route structure after picking up Sun Country after its second bankruptcy. Today, Sun Country leases 26 Boeing 737s and flies to about three dozen destinations from MSP. Its routes vary seasonally.

Davis said the airline is profitable. Still, its performance has been near the bottom of an industry that has been thriving for the last few years.

Sun Country earned $5 million on $136 million in revenue during the third quarter, a turnaround from a loss of $6 million on revenue of $117 million in the same period a year ago, according to an Airline Weekly analysis of data released this week by the U.S. Bureau of Transportation Statistics.

It became clear that changes were afoot earlier this year when the Davis brothers hired Bricker. Shortly after arriving, Bricker praised Sun Country’s employees, service and brand reputation but he said, “The results aren’t there.”

He immediately took steps to lower costs and generate more revenue. The airline imposed some new fees, including one for putting a carry-on bag in an overhead bin. And it started to increase the number of seats in its planes.