If you want to fly the “hometown airline” from the Twin Cities to Chicago, the window of opportunity is closing.

Sun Country Airlines’ last flight between Minneapolis-St. Paul International Airport and Chicago Midway is Sept. 28.

Larry Chestler, Sun Country’s executive vice president of business development, confirmed Tuesday that the airline was ending the route. “It’s been that way on the website for months but never formally announced,” he said.

With only 20 planes in its fleet, the company decided to reconfigure its schedule mostly in international markets. “When you have scarce resources, sometimes you have to make trade-offs to satisfy the market,” Chestler said.

Sun Country started two daily round trips to Midway in July 2013. But with as many as 44 flights daily between MSP and Chicago, O’Hare and Midway combined, the competition was always tough for Sun Country.

American and United have hubs in Chicago, and Delta does here. As a result, said Steve Loucks, chief communications officer for Travel Leaders Group in Plymouth, “It was the dominance of those three, and Southwest, that made it so price-competitive. It was typical to get a round-trip ticket under $200 or $150.”

Chestler said the Mendota Heights airline found its most direct competition with Southwest, which also flies out of Terminal 2. “They had a greater flight frequency than our schedule,” he said. Spirit Airlines, which often has fares as low as $35 one way, also siphoned off some of Sun Country’s leisure passengers.

Sun Country is also dropping year-round flights from MSP to Lansing, Mich., and seasonal flights to Harlingen, Texas. Next month, it will add a second daily nonstop flight to Washington National, and provide year-round service from Fort Myers, Fla., to San Juan, Puerto Rico, and Cancun, Mexico.

Sun Country has had a turbulent run since its inception in 1982. Once owned by Tom Petters, it emerged from bankruptcy in 2011, but pilots have been threatening to strike, claiming they are the lowest paid in the country, according to the Air Line Pilots Association. The company has threatened to downsize or shut down. Discussions are scheduled for later this week, Chestler said.

As the MSP to Chicago schedule winds down, consumers can get fares as low as $41 each way for some remaining flights to Midway.