WARSAW, July 10 (Reuters) - The organisation that runs air traffic control in Poland could lose airline fees amounting to over 80% of its income due to a Belgian court ruling in a case brought by U.S. drugmaker Pfizer against Poland over payment for COVID-19 vaccines, it said on Friday.

Polish Air Navigation Services Agency (PANSA) said it had been informed by the Brussels-based European Organisation for the Safety of Air Navigation (Eurocontrol) that money due to it from fees from airlines had been seized in connection with April's ruling.

PANSA said it was preparing a formal objection since the case was unrelated to its operations, but was taking steps to secure financial resources for uninterrupted operations.

The court ordered that Poland and Romania take delivery of €1.9 billion ($2.2 billion) worth of COVID-19 vaccines made by Pfizer PFE.N and BioNTech 22UAy.DE, including €1.3 billion for Poland alone, under contracts signed during the pandemic.

In April 2022, Warsaw refused to comply with the contract, citing the slowing pandemic, the war in Ukraine and possible abuse of dominant position by Pfizer.

"The receipt of an enforcement order by Eurocontrol means that it is obligated to withhold all funds from en route charges to PANSA – both currently collected and future payments – until Pfizer's claim is satisfied or the case is otherwise resolved," PANSA said in a statement.

Romanian air traffic controller Romatsa confirmed last week that Eurocontrol had enforced a precautionary seizure on its account, targeting 3.4 billion lei ($743 million) and recovery costs of €18.5 million. The government has said Romatsa will appeal the measure in Belgium and that the seizure would not halt its operations.

Eurocontrol had no comment.

Polish Prime Minister Donald Tusk, who blames the previous government for the situation, told a news conference the government would not leave PANSA without help, but the general situation was "quite ugly".

"Our legal battle is ongoing, but the threat is obvious," he said.

Belgium's Justice Ministry did not immediately respond to an emailed request for comment.

Pfizer said in an email that "the Belgian court's judgment reflects the importance of the contractual obligations that underpinned a successful European pandemic response", and that the company was taking appropriate steps of legal enforcement.

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