SYDNEY, Oct 24 (Reuters) - A U.S. law firm has filed a class...

SYDNEY, Oct 24 (Reuters) - A U.S. law firm has filed a class action suit against mining giant Rio Tinto (RIO) , which is facing U.S. Securities and Exchange Commission (SEC) fraud charges stemming from an ill-fated investment in Mozambique coal mining.

Seattle-based Hagens Berman Sobol Shapiro LLP said in a statement released in Australia on Tuesday it filed the suit on behalf of purchasers of Rio Tinto American Depositary Receipts (ADRs) between Oct. 23, 2012 and Feb. 15, 2013 in the U.S. District Court for the Southern District of New York.

Hagens Berman did not specify the purchasers, nor disclose financial details of the suit. The firm did not immediately respond to a request for comment.

Rio Tinto declined to comment on the filing, the first publicly announced class action suit involving the coal asset.

The SEC last week charged Rio Tinto and two of its former top executives with fraud, saying they inflated the value of Mozambique coal assets in Mozambique acquired for $3.7 billion and concealed critical information while tapping the market for billions of dollars.

Rio Tinto and the two former executives have denied the charges.