AIRLINES

United to Limit Use of Devices: The airline said that, effective July 1, it will join other carriers in prohibiting passengers from operating devices such as laptop computers and compact disc players during takeoffs and landings. The airline said use of such equipment could cause electromagnetic interference with cockpit navigation and communications systems. Passengers will be allowed to use the devices once the plane is at or above 10,000 feet, an altitude usually reached within 10 minutes of takeoff and retained until the final 10 minutes of a flight.