CHICAGO – United Airlines, citing continued soft passenger demand in the wake of September’s terrorist attacks, announced Monday it will downgrade service in several cities at end of the month.

Elk Grove Village-based United will withdraw service from Allentown, Pa.; Knoxville, Tenn.; Norfolk, Va.; Portland, Maine; Raleigh-Durham, N.C., and Santa Barbara, Calif., and replace it with United Express, its regional carrier.

The world’s second-largest airline also will end all service in Little Rock, Ark.; Bellingham and Yakima, Wash.; Lynchburg, Va. and Victoria, British Columbia.

It also will end United Express service between Washington-Dulles and Allentown, Pa.; Cincinnati, Akron and Canton, Ohio; Louisville, Ky., and Knoxville, Tenn., and non-stop service between Washington Dulles and Sacramento, Calif.

“We regret the need to make these decisions, which are obviously driven by the terrorist attacks on our country and soft passenger demand we have been experiencing,” United President Rono Dutta said.

Like the rest of the airline industry, United has reported a sharp decline in passengers in the wake of the Sept. 11 attacks on the World Trade Center and the Pentagon.

Since the attacks, the airline has reduced its schedule from 2,400 flights to 1,900 flights daily. Last week, the airline announced that it will fly 69 percent of its schedule beginning Nov. 1. United also has said it will cut at least 20 percent of its work force of about 100,000.