PORTLAND — Verso Paper Corp. reached a settlement with federal antitrust regulators to buy its larger competitor NewPage for about $1.4 billion, putting a long-sought deal to restructure both companies that produce coated paper near completion.

Verso announced the breakthrough for the deal Wednesday morning, stating that the two paper makers reached a settlement that needs approval from the U.S. District Court of the District of Columbia, requiring Verso to sell off its mill in Rumford and another in Biron, Wisconsin.

It announced plans to sell those mills earlier this year to the Canadian company Catalyst Paper Corp. in order to advance the merger.

The company said it plans to close the merger with NewPage in January 2015. It would sell the Rumford mill as part of that merger and continue to operate the mill in Jay operated by Verso, which closed its Bucksport mill earlier this year.

The company said at the time that the Bucksport closure was not part of its merger plans with NewPage and did not state that was part of the settlement with the U.S. Department of Justice’s antitrust division.

The combined company would own three mills in six states and have about $3.5 billion in annual sales. Company officials have said the merger would result in savings from shared overhead and other efficiencies.

“The combination of Verso and NewPage will create a stronger, more stable company that will be better positioned to serve our customers and compete in a competitive global marketplace,” said David J. Paterson, Verso’s president and chief executive officer. “We are pleased that we were able to address the concerns of the Justice Department while preserving the benefits of the transaction for our stockholders and customers.”

Verso’s executives will continue to lead the combined company.