Flights from London City airport to Lisbon are being introduced by TAP Air Portugal.
Two departures a day on weekdays will run from October 27 in addition to existing services to the Portuguese capital from Heathrow and Gatwick.
The airline is to use a 106-seat Embraer 190 aircraft on the route – the only connection to Lisbon from the London docklands airport.
Flights will leave London City at 10.20am and 7.50pm on Mondays to Fridays with daily flights on Saturdays and Sundays.
The expansion follows a 20.3% increase in the number of passengers using the airline to travel between London and Lisbon in the first quarter of 2017 over the same period last year.
TAP offers connections via Lisbon to a long-haul network covering Africa and the Americas.