The grounding of UK leisure carrier Thomas Cook Airlines is likely to spark interest in the airline’s slot portfolio at London Gatwick Airport, although the slots are highly seasonal.

In the early hours of Sept. 23, Thomas Cook said it had entered compulsory liquidation after last-ditch talks to save the UK business failed. Thomas Cook Airlines was immediately grounded.

Gatwick is a highly constrained airport and slots are a sought-after commodity.

ATW understands that Thomas Cook Airlines holds around 18 daily summer slot pairs at Gatwick and roughly nine daily pairs in winter.

Industry sources noted the airline holds an unusual set of slots because it is a primarily a leisure charter carrier. This means the slots are “seasonally imbalanced” and timed at irregular hours, on various days of the week, impacting the value of the portfolio and making it less attractive to would-be buyers.

There is also the question of who owns the slots once an airline ceases to operate, but this was clarified by a recent legal precedent that was set by the administrators of insolvent UK leisure carrier Monarch Airlines. In late 2017, the UK Court of Appeal ruled that Monarch’s administrators could keep airport slots previously held by the carrier, generating funds from their sale to pay off creditors.

“There will be the same questions, as in the case of the Monarch collapse, as to whether the administrators will be able to trade the slots that have a value. In the case of Monarch, after some legal to and fro, the administrators did receive that value, so that would seem to be a precedent for Thomas Cook. We think that the slots that have value are those at Gatwick, where the precedent is that slot pairs have a value in the millions of pounds,” consultancy firm ICF said.

Airport Coordination Ltd. (ACL) handles slot allocations for 38 airports in seven countries, including Gatwick’s slot pool. In Monarch’s case, ACL said it was not consistent for slots to be allocated to an airline with no pilots or aircraft, whose air operator’s certificate had been revoked and that had no realistic prospect of operating again.

At the time, ACL said the ruling—which allowed a defunct airline to obtain and trade slots—set a worrying precedent for the future.

 “Thomas Cook Airlines’ operating license remains valid and therefore it continues to hold slots at airports coordinated by ACL. ACL is working to ensure that slots are available for repatriation flights organized by the CAA,” ACL told ATW.

Thomas Cook Airlines operated a fleet of 34 aircraft, comprising 27 Airbus A321-200s and seven A330-200s.

According to an ICF analysis, Manchester and London Gatwick airports are the hardest hit by the airline’s collapse. Over the past 12 months, Thomas Cook Airlines made up 9% of seats at Manchester and 4% of seats at Gatwick.

“Looking at the routes that Thomas Cook Airlines flies, the airlines with the biggest overlap (and hence stand to win initially from less competition) are Jet2, TUI and [UK LCC] easyJet. We would expect the LCCs to back fill a large part of this market, as we saw with Monarch Airlines. It is worth bearing in mind that this is a larger collapse than Monarch. Thomas Cook was the UK’s seventh largest carrier with over 8 million passengers per year (around 3% of total UK demand), while Monarch [carried] around 6 million annual passengers,” ICF said.

Victoria Moores,