Midwest Air Group Inc. will cut daily flights to 11 U.S. cities including San Diego, Baltimore, St. Louis and two Florida destinations as the airline grounds a third of its fleet to counter soaring fuel costs.

Midwest will stop flying on Sept. 8 to Fort Lauderdale and Fort Myers in Florida as well as San Diego, the company said in a statement. The airline will keep its service to Los Angeles and Seattle, through passengers will travel through Kansas City, Missouri, similar to its San Francisco route, the company said.

Another eight cities including Baltimore; Hartford, Connecticut; Louisville, Kentucky; St. Louis and San Antonio will be dropped from its Midwest Connect regional jet service after Sept. 8, Midwest said.

The airline also said it will no longer offer daily flights to Orlando, Florida, from Milwaukee, though it will fly passengers there between October and April.

The airline had served 47 cities at the beginning of the year, the company said. Before today’s announcement, the carrier had suspended flights to Austin, Texas; Charlotte, North Carolina; Colorado Springs, Colorado; and Duluth, Minnesota, Midwest said. The airline will continue to serve 32 cities.

Last month, Midwest grounded all 12 of its less fuel- efficient Boeing Co. MD-80s, in response to a 36 percent increase in the price of jet fuel this year, leaving it with a fleet of 25 smaller Boeing 717s.

The company was acquired in February for $440 million by Northwest Airlines Corp. and TPG, the private-equity firm run by David Bonderman.