British Airways will launch flights from Heathrow to Preveza in Greece and Bastia in Corsica next summer.
Flights are now on sale for both routes.
Flights to Preveza will operate on Wednesdays and Sundays from May 26 through to September 29.
Fares start from £71 one-way in Euro Traveller and £198 in Club Europe.
Flights to Bastia will operate every Saturday from May 25 to September 28 and follow the launch of a new service to the Corsican airport of Figari earlier this year.
Bastia fares start from £48 in Euro Traveller and £128 in Club Europe one-way.
BA is also increasing the number of flights from Heathrow to Marseille, Budapest, Gibraltar, Palermo, Amsterdam and Malaga.
A new service from Gatwick to Kos starts on May 15.
Flights from London City will also be boosted, with additional frequencies on Ibiza, Edinburgh and Berlin.
