The Monarch failure reduced passenger growth at Gatwick last month.
The airport was still able to achieve a record October as passenger numbers climbed by 1.4% to 3.9 million year-on-year, including a 13.3% rise in long haul traffic, but down on the 2.7% growth recorded in September.
The slowdown at the UK’s second largest airport was affected by Monarch ceasing trading at the start of the month.
Monarch accounted for 4.5% of the airport’s flights, or an average of 285 flights a week.
Prior to Monarch entering into administration, Gatwick’s passenger growth was 7.1% as a monthly average this year, with annual traffic growth remaining at 6.5% on a moving annual basis.
There is strong interest amongst airlines to take over the slots operated previously by Monarch, according to the airport.
Among the the best performing routes were Hong Kong, up 44%; New York 46.5%, Los Angeles 44.5% and Vancouver 22.2%.
Regional connectivity continued to perform strongly with Inverness up 11%, Edinburgh 7.3%, Isle of Man 7.1% and Newquay 5.9%.
Chief executive, Stewart Wingate, said: “We’re on the verge of serving 46 million passengers this year, up from 31 million in 2010. That’s a 50% increase in total passenger numbers in just seven years.
“Alongside this passenger growth we’ve also invested to improve experience at the airport, reducing queuing times, adding more choice in retail, improving our on-time performance and achieving record-levels of passenger satisfaction.
“Passengers are voting with their feet to choose Gatwick – all we need now is a way to satisfy their growing demand.”