* NMC shares jump 37%, on track for best day ever
* Confident that review outcome will match its disclosures
* Muddy Waters launched short attack on NMC last week
* If gains hold, NMC could add about 1 bln stg to market cap (Recasts, adds share move, trader comment)
Dec 23 (Reuters) - NMC Health shares rebounded by more than 30% on Monday after the healthcare group said it would launch an independent review of its books, seeking to reassure investors after short-selling firm Muddy Waters questioned its finances.
Last week Muddy Waters took a short position in UAE-based NMC and challenged the value of its assets and cash balance, as well as reported profits and debts, triggering a major sell-off in the stock that had wiped out half its market value as of Friday's close.
NMC, the largest private healthcare provider in the United Arab Emirates, said on Monday the review would be undertaken by an unidentified accounting firm and overseen by a committee of independent NMC non-executive directors.
"We are confident that this review, when complete, will be entirely confirmatory of the disclosures provided by the company to date," NMC said.
Its shares rose as much as 37% to a session high of 1,785 pence in mid afternoon trade on Monday. If the gains hold, the company is on track for its best day ever, cutting its losses for the year so far to about 35%.
The upbeat commentary from NMC, as well as low trading volumes ahead of the holiday season and investors looking to make some profits, also exaggerated the stock movement, a trader said.
The healthcare provider's market capitalisation stood at 2.72 billion pounds ($3.5 billion) by Friday's close. At Monday's session high, that valuation would be about 1 billion pounds higher.
The company, which in 2012 became the first from Abu Dhabi to list on the London Stock Exchange, last week stood by its 2019 and 2020 forecasts, and issued a detailed response to the allegations from Muddy Waters.
Short selling involves borrowing an asset and selling it with the aim of buying it back at a cheaper price and making a profit.
About 10% of NMC's outstanding shares were in short position as of Dec. 13, according to FIS data.
Muddy Waters, founded by American Carson Block, is known in financial markets for declaring short equity positions on the basis of its in-house research.
The company had no immediate comment on Monday on NMC's decision to launch an independent review. (Reporting by Pushkala Aripaka in Bengaluru; Additional reporting by Maiya Keidan; Editing by Saumyadeb Chakrabarty and Mark Potter and Susan Fenton)