UAL Corp.'s United Airlines said Wednesday it plans to phase out its United Shuttle as it sees less demand for the quick-turnaround service after the Sept. 11 attacks. 

United, the No. 2 U.S. airline, said it would incorporate shuttle flights into its mainline and United Express service this fall. The change will go into effect Oct. 31. 

The carrier said the move was part of its fleet readjustments after the attacks on the World Trade Center and the Pentagon building three weeks ago. Phasing out the shuttle would allow it more flexibility in using large or small aircraft to match market demand, the airline said. 

United shuttle service operates mainly in the western United States with a fleet of 59 Boeing 737 aircraft. 

United shares closed up 28 cents at $19.33 at the end of trading on the New York Stock Exchange.