* Monarch overturns High Court ruling
* Administrators seek money from sale of valuable London slots
* Costs from Monarch slots not expected to be material - easyJet (Adds details from ruling, reaction)
LONDON, Nov 22 (Reuters) - Collapsed airline Monarch has won an appeal against a court decision that had stripped it of rights over valuable airport slots, in a boost to administrators who are hoping to recover money for creditors.
Adminstrators at KPMG hope to raise capital by transferring the slots at London's Gatwick and Luton airports to other airlines.
"We are delighted with the ruling," said Blair Nimmo, partner at KPMG and joint administrator. "We will now progress the slot exchange transactions we have underway, whose buyers will be announced at completion."
Monarch collapsed suddenly at the start of October, immediately ceasing operations, forcing the repatriation of over 100,000 customers by the Civil Aviation Authority (CAA).
The High Court's initial ruling on Nov. 8 said that as the airline had no planes and retains just three trained pilots, who currently hold management positions, the Airport Coordination Limited (ACL) - an independent slot co-ordination company - had no duty to assign it slots for summer 2018. The CAA subsequently revoked Monarch's operating license.
However, the Court of Appeal ruling found that despite this, Monarch was still an air carrier when slots fell to be allocated last month and in fact remains one.
"It may be a failed air transport undertaking but that need not stop it being an air transport undertaking," judge Guy Newey said in the ruling.
ACL said it would not appeal, but was concerned about the implications of the ruling.
"The fact that a defunct airline is able to obtain and trade slots, sets a worrying precedent for the future and one which will give cause for concern to airlines and airports," it said in a statement.
Monarch estimates its slots could be worth around 60 million pounds ($80 million). While the appeal only applies to Gatwick and Luton, these slots are the airline's most sought-after assets.
EasyJet, IAG, Wizz and Norwegian have all expressed interest in the slots at the London airports. The High Court ruling that Manchester and Birmingham slots should be returned immediately to the slot pool to be re-assigned by the ACL was unaffected by Wednesday's appeal.
EasyJet's CFO Andrew Findlay told reporters not to "believe everything you read" about the reported value of the slots, saying that 60 million pounds was a "high-end" number.
"Any costs associated with Monarch slots will not be material," chief executive Carolyn McCall said after results on Tuesday. (Editing by Stephen Addison)