Passengers in India were subject to "Airport Development Fee" that went as high as Rs 1,300 per person, which was challenged by a consumer rights group.
In August 2009 the Delhi High Court ruled in favour of the airports, which included the Delhi and Mumbai ones, saying that the fee was justified. The government had argued that airport infrastructure could not be improved without contribution from passengers.
But the Supreme Court on Tuesday, backed the consumer rights group which said the additional fee levied by Delhi International airport Limited (DIAL) and Mumbai International Airport Limited (MIAL) did not benefit passengers.
The ruling sent the stocks of GVK Power and GMR Infra, which operate the Mumbai and Delhi airports respectively, down two and four percent.