BRUSSELS (AFP) - Brussels said on Monday (July 26) it had extended rules aimed at avoiding "ghost flights" by carriers trying to keep airport slots as they struggle to recover from the Covid-19 pandemic.

"As the aviation industry begins to recover from the impact of the Covid-19 crisis, the European Commission remains determined to maintain the relaxation of ordinary slot allocation rules for airlines," a statement said.

"The relief will therefore be extended to the next winter planning season, which runs from Oct 31, 2021 to March 27, 2022."

The regulation lowers the requirement for airlines to fly at least 80 per cent of the time to hold on to highly-prized take-off and landing slots at airports to 50 per cent.

The rules were relaxed last year with the aim of cutting down on the number of empty or near-empty "ghost flights" as airlines carried on flying despite steep drops in passenger numbers.

Initially, Brussels gave the carriers a complete waiver for maintaining slots but then hiked the required quota of flights back up to 50 per cent ahead of this year's summer season.

Some airline representatives have slammed the decision to maintain that figure into next year as "out of touch with reality" and insisted the threshold needs to be lowered for the upcoming winter months.

The International Air Transport Association (IATA) complained that the rules "restrict the ability of airlines to operate with the agility needed to respond to unpredictable and rapidly changing demand, leading to environmentally wasteful and unnecessary flights".

"It will also further weaken the financial stability of the industry and hinder the recovery of the global air transport network."

The IATA said the European Commission's assertion that an uptick in travel this summer justifies maintaining the 50 per cent rate "flies in the face of significant evidence of the uncertain outlook for traffic demand this winter".