Jet2.com and Jet2holidays has increased capacity from former Monarch bases Birmingham, Manchester and Leeds.
More than 100,000 winter seats have been added in response to what the airline and tour operator has described as “increased demand”.
Monarch, which flew from all three airports, ceased trading earlier this week.
The new additions include 50,000 more seats at Birmingham, where it started flying from in March. Capacity will increase on its routes from Birmingham to Alicante, Faro, Gran Canaria, Lanzarote, Malaga, Majorca, Rome and Tenerife.
An additional 45,000 sats from Manchester have been added – to Alicante, Faro, Fuerteventura, Lanzarote, Malaga and Tenerife.
There will also be three extra weekly flights to Tenerife from Leeds Bradford – meaning 15,000 extra seats are on sale from its main base.
The airline – which said it “won’t be stopping” with the extra flights – will base an additional two aircraft at Birmingham as part of the move, taking the number based at the airport to six.
Jet2.com and Jet2holidays is also adding 14 extra services from Stansted – where it began flying from earlier this year – to Tenerife, Lanzarote, Alicante, Majorca and Faro after “strong demand for flights and holidays in October and November” and “particularly the half-term holidays”.
Steve Heapy, CEO of Jet2.com and Jet2holidays said: “A number of factors have resulted in increased demand for our award-winning flights and Atol protected package holidays right across the UK.
“To meet that demand we have added extra capacity from Birmingham, Manchester, Leeds Bradford and London Stansted airports so that holidaymakers can continue to reach their favourite winter sun and city destinations from their local airport.
“We won’t be stopping at these winter flights, so keep an eye out for further announcements about additional Summer 18 capacity very soon.”