The second-biggest U.S. airline said Comair, which serves Delta's (DAL.N) midwest and east coast hubs, will cease operations after September 29.

"While regional flying has and will remain a key component of Delta's network, customer expectations and the unit costs of regional flying have evolved," Don Bornhorst, senior vice president of Delta Connection, said in a memo to employees.

The shutdown will not result in major changes to Delta's network, the company said.

Comair had about 1,700 employees as of March, according to its website.

Cincinnati-based Comair accounts for about 1 percent of Delta's network capacity. Its fleet is comprised entirely of Bombardier's (BBDb.TO) 50-, 65- and 76-seat Canadair Regional Jets.

Atlanta-based Delta recently said it plans to reduce the number of 50-seat regional jets from about 350 to 125 or fewer in the next few years.

Delta shares rose 1 percent to $9.53 on Friday on the New York Stock Exchange.

(Reporting by A. Ananthalakshmi in Bangalore; Editing by Rodney Joyce, Sreejiraj Eluvangal)

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