By Sonali Paul

MELBOURNE (Reuters) - Australia's corporate watchdog said on Friday it has launched court action against miner Rio Tinto and two former executives for misleading investors about the coal reserves it reported in a $4 billion (2.9 billion pounds) acquisition in Mozambique.

The Australian Securities and Investments Commission said the company, its former Chief Executive Tom Albanese and former Chief Financial Officer Guy Elliott had made deceptive statements in their 2011 annual report, published in 2012.

"ASIC alleges that RTL (Rio Tinto Ltd) engaged in misleading or deceptive conduct by publishing statements in the 2011 annual report, signed by Mr Albanese and Mr Elliott, misrepresenting the reserves and resources of RTCM (Rio Tinto Coal Mozambique)," the commission said in a statement.

"We will respond once we have had an opportunity to consider the allegations in full," Rio Tinto said in an emailed statement.

Rio shares were down 0.8 percent at 3,748 pence in early trade in London.

The company has denied any wrongdoing in a similar case brought by the U.S. Securities and Exchange Commission.

Rio Tinto now faces court cases in the United States and Australia over its disastrous acquisition of Riversdale in Mozambique, with the U.S. SEC having charged the company, Albanese and Elliott with fraud.

"The outcomes of these matters, and associated class actions that have been commenced on behalf of securities holders, remain uncertain, but they could ultimately expose the Group to material financial cost," Rio Tinto said in its 2017 annual report released on Friday.

ASIC said it is asking the court to declare that Rio Tinto broke the Corporations Act, is seeking monetary penalties against Albanese and Elliott and is asking the court to bar them from managing corporations "for such periods as the court thinks fit".

The commission is continuing investigations into the circumstances surrounding the impairment of the Mozambique coal assets, it said, declining to comment further.

Rio Tinto bought Riversdale for $4 billion in 2011, wrote off about $3.5 billion of its value and sacked Albanese and other executives involved in the deal in 2013.

The Mozambique writedown followed hefty writedowns on a previous acquisition.

The SEC alleges that the company and executives inflated the value of coal assets in Mozambique and concealed critical information while tapping the market for billions of dollars.

The company, Albanese and Elliott have all said they would vigorously defend themselves against the allegations.

Rio Tinto has already reached a settlement with Britain's Financial Conduct Authority, agreeing to pay a fine of 27 million pounds for breaching accounting rules in connection with the Mozambique assets.

"The investment in 2011 of $4 billion in Mozambique in what ultimately turned out to be inferior quality coal assets was undoubtedly a low point during my tenure," outgoing Chairman Jan du Plessis said on Friday in his final annual report with the company.

(Additional reporting by Barbara Lewis in London; editing by Richard Pullin and Jason Neely)