ADCB, which is one of NMC Health PLC's 80 Gulf and international creditors, said the move was aimed at safeguarding the future of the London-listed company and its subsidiaries.

ADCB said last week its exposure to NMC Health was about $981 million, as the London-listed company recently revised its debt position to $6.6 billion, much higher than earlier estimated.

NMC, the biggest private healthcare provider in the United Arab Emirates, has seen its stock more than halve in value since December and trading in its shares was suspended in February.

The decline was triggered by a report by short seller Muddy Waters that questioned the company's financial statements.

The ADCB's High Court filing came before NMC Health's new executive chairman said earlier on Saturday he would work with authorities in Britain and the United Arab Emirates (UAE) to recover misused funds and called on the company's creditors for a debt standstill.

(Reporting by Saeed Azhar; Editing by Helen Popper)