Index provider MSCI said on Thursday it was reviewing the free float status of Adani Group securities after market participants raised concerns about the eligibility of companies in the Indian conglomerate for some of its indexes.

"MSCI has received feedback from a range of market participants concerning the eligibility and free float determination of specific securities associated with the Adani Group for the MSCI Global Investable Market Indexes (GIMI)," it said in a statement.

MSCI said it defined the free float of a security as the proportion of shares outstanding available for purchase in the public equity markets by international investors.

"MSCI has determined that the characteristics of certain investors have sufficient uncertainty that they should no longer be designated as free float pursuant to our methodology," the statement said.

"This determination has triggered a free float review of the Adani Group securities."

Adani Group did not immediately respond to a Reuters request for comment.

Seven key Adani companies have lost at least a combined $110 billion in value after U.S based short seller Hindenburg Research alleged improper use of offshore tax havens and stock manipulation by the conglomerate.

Adani Group has rejected the criticism and denied any wrongdoing.

MSCI said the Adani review would be carried out as part of its regular February review. The results of that were due to be published later Thursday.

The index provider said in late January it was seeking feedback from market participants as the sell-off crisis engulfed Adani. (Reporting by Scott Murdoch in Sydney and Rhea Binoy in Bengaluru; Editing by Shailesh Kuber and Edwina Gibbs)