United Airlines, a unit of United Continental Holdings (NYSE: UAL), has announced a major expansion that includes 4 new cities and 31 new routes. United president Scott Kirby said, “Starting this summer we ‘re offering more flights to more destinations at more convenient times than in recent memory.” Most of the new flights are beginning on June 8.

The expansion brings United to four destinations it does not currently serve. Three of those cities are Champaign, Ill.; Columbia, Mo.; and Rochester, Minn. in the Midwest. The other is Santa Rosa, Calif. on the West Coast.

The expansion adds 16 non-stop routes to the carrier’s route map. The airline also unveiled the addition of six seasonal routes. United Airlines will also be boosting the number of flights on 15 routes it’s already flying.

United said that service from Chicago to Tucson, Arizona will expand to a daily frequency. Existing service from Chicago to Fort Lauderdale and Fort Myers in Florida will increase to three times daily and 2 times daily respectively. Internationally, United is adding a new daily nonstop from San Francisco International Airport to Munich, Germany starting May 24.

United is adding more flights and bigger planes to key business routes. United’s new Boeing 777-300ER will be introduced on its San Francisco-Hong Kong route starting next month. Its Newark-Tel Aviv route will be the second to get the Boeing 777-300ER, with flights starting on May 5.

The route expansion is the latest effort to turn around the airline. United has recently announced other changes to its services, including upgrades to some of its hub airports and its new “Polaris” business class offering. United hopes its changes will help it win back customers lost to rivals in recent years. The expansion comes just in the time for the peak summer travel season this year.

Scott Kirby, president of United, said, “We’ve been shrinking, and our competitors have been growing at our expense.” United is currently the third largest airline in the U.S., behind American Airlines in first place and Delta Airlines in second. Kirby says, “We have to turn that around.”

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