Sept 18 (Reuters) - Diversified U.S. miner and energy producer Freeport-McMoran Inc said it has filed to sell additional shares to raise up to $1 billion.
The company also raised $1 billion in gross proceeds through the sale of 96.7 million shares that was announced on Aug. 10.
The second offering comes less than a month after activist investor Carl Icahn disclosed an 8.5 percent stake in Freeport, calling the company "undervalued".
Freeport, whose market value is about $12.53 bln as of Thursday's close, had a total debt of $20.31 billion as of March 31.
Arizona-based Freeport had slashed its mining capital budget by 25 percent for 2016 and cut 10 percent of its U.S. mine staff last month to cope with the slump in commodity prices.
Freeport's shares were down 4.2 percent at $11.54 in premarket trading. (Reporting by Sneha Banerjee in Bengaluru; Editing by Anil D'Silva)