LONDON (Bloomberg) — British Airways Plc, Europe's third-biggest airline, plans to charge passengers a fee to book their seats in advance as the carrier seeks to boost revenue amid the slump in air travel.

The carrier, based in London, will give its customers the option of choosing their seats for a fee at the time of buying their tickets starting October 7. Passengers will still be able to select without charge seats that haven't been reserved up to 24 hours before a flight's departure.

"We're giving another option to our passengers," said Philip Allport, a London-based spokesman for British Airways, by telephone. "If somebody wants to have a window seat, they now have the option to secure that."