Covanta Holding Corp.’s board of directors have authorized the repurchase of  $100 million of the company's stock.

The repurchase brings the total buyback authorized to $400 million, the company said in a press release.  From the third quarter of 2010 through the second quarter of 2011, Covanta has repurchased more than 13.5 million shares at a cost of about $219 million, representing approximately 8.8 percent of the outstanding common stock.

The Morristown, N.J.-based Covanta said it expects to fund the repurchases through available sources of liquidity, including cash from its business and proceeds from asset sales.

“Today’s announcement demonstrates our commitment to continue to actively return capital to shareholders in the absence of any immediate investment needs for core growth opportunities,” said Sanjiv Khattri, Covanta’s executive vice president and chief financial officer. “We believe that our dividend and stock repurchase programs are important aspects of our continued efforts to enhance shareholder value.”

In addition, Covanta directors declared a quarterly cash dividend of $0.075 per share, payable on October 14, 2011 to stockholders of record as of the close of business on October 3, 2011.