Covanta Holding Corp. posted a net loss for its first quarter on slightly higher revenue.

The Morristown, N.J.-based waste-to-energy company said in a news release it had a net loss from continuing operations of $11 million, compared with a loss of $14 million in the year-ago period, ending March 31. Operating income reached $5 million compared with a $2 million loss in the previous year.

Covanta said the operating income increase came from organic growth initiatives for recycled metals and various operational improvements, which more than offset factors like lower energy pricing and a reduction in alternative fuel tax credits.

Operating revenues rose 4 percent to $392 million compared with $377 million in 2011.

"Our operational and financial performance continues to be predictably strong,” said Covanta president and CEO Anthony Orlando. “In addition, I am very pleased with the progress we are making on our organic growth and other initiatives.”