DUBAI  - Abu Dhabi Commercial Bank (ADCB) is in talks with troubled UAE hospital operator NMC Health to tackle the company's financial defaults, the bank said on Thursday.

ADCB has an exposure of about $981 million to NMC, which represents less than 1% of the bank's total assets, it said.

"The bank has initiated discussions with the NMC Health Group and other substantial creditors to implement appropriate solutions to address the company's financial defaults, governance and other issues," it said in a bourse filing.

London-listed NMC, which could not be immediately reached for comment, has recently revised its debt position to $6.6 billion, much higher than earlier estimated.

The company, which has been in crisis since U.S. firm Muddy Waters questioned its financial statements in December, has also recently named a chief restructuring officer to resolve its indebtedness woes.

ADCB, one of more than 80 local, regional and international banks that gave credit to NMC, said it was provided through a combination of loans from the bank, as well as Union National Bank and Al Hilal Bank, before the three merged last May.

It said it was not able to quantify anticipated impairments due to "rapidly evolving" developments at the company.

"ADCB is deeply concerned by NMC Health Group's recent announcements of previously undisclosed liabilities of over $4 billion," it added.

NMC shares were left with a value of 938 pence when suspended in late February, a far cry from the 2,631 pence at which they traded before the questions from Muddy Waters.

(Reporting by Davide Barbuscia; Editing by Clarence Fernandez) ((Davide.Barbuscia@thomsonreuters.com; +971522604297; Reuters Messaging: davide.barbuscia.reuters.com@reuters.net))