Vueling is launching a three times weekly service from Cardiff to Alicante from June 24.
The service will operate on Tuesdays, Thursdays and Sundays using 150-seat Airbus A319 aircraft.
The flights were originally scheduled to end in the middle of September, but operations will now run to October 27 due to high demand.
From September 16 the Cardiff-Alicante route will switch to Mondays, Wednesdays and Saturdays.
New to Cardiff Airport for 2012, Vueling already operates three scheduled flights per week (Tuesdays, Thursdays and Saturdays) to Barcelona-El Prat Airport on Airbus A320 aircraft.
On June 24, Vueling will also bolster its route network from Cardiff with services to Palma de Mallorca, operating on Tuesdays, Thursdays and Sundays.
