Verso Paper Corp. has successfully completed a critical debt restructuring plan that paves the way for its acquisition of NewPage Holdings, a merger that would create the largest glossy paper producer in North America and the state’s largest paper industry employer.

As part of the $1.4 billion deal, which was first announced in January, Verso had agreed to pursue a debt restructuring plan that involved convincing some of its debt holders to exchange their notes for new debt agreements with different terms.

While the company’s earlier attempts to complete this debt exchange offer were unsuccessful, it sweetened the deal last week and set a deadline for midnight July 30 for the majority of debt holders to agree to the exchange.

Verso announced Thursday morning that the debt exchange was successful. “We thank our noteholders for their strong support that has helped us satisfy the minimum participation conditions for the exchange offers,” Verso CEO Dave Paterson said in a statement. “We have made significant progress to completing our acquisition of NewPage.”

There were two classes of debt holders targeted for the exchange. Holders of approximately $299.4 million of what the company called “Old Second Lien Notes” agreed to the exchange, which represented approximately 75.6 percent of all outstanding notes in that class. That exceeded the 75 percent minimum participating rate for that class.

Verso also received for exchange approximately $102 million of what the company calls “Old Subordinated Notes,” which represents approximately 71.6 percent of the total outstanding amount. That exceeds the 70 percent minimum participation in that class needed to satisfy the merger deal.

The merger would combine Verso Paper and its three paper mills, including those in Bucksport and Jay, with NewPage’s eight paper mills, including one in Rumford. The new company would continue to operate under the Verso name and would control more than half of the North American market for the glossy paper used in magazines and retail catalogs.

If the deal closes, the new Verso would employ about 2,230 people in Maine, roughly a third of all paper industry workers in the state.

Both companies have struggled amid declining demand for coated paper because of international competition and increasing use of electronic devices. Verso is highly leveraged and carries $1.2 billion in debt, according to its 2013 annual report. In 2011, NewPage filed for bankruptcy, emerging a year later.

Paterson has said that the merger would create $175 million in savings in the first 18 months after the deal closes.

The merger, however, is not a done deal. It still faces regulatory approval, which could be challenging given the antitrust concerns raised by the fact the merger would create a company that controls more than 50 percent of the North American market for glossy paper.

Opinions are split on whether those antitrust concerns will derail the merger. Reuters polled five antitrust experts on the prospect that the deal is approved. Three of the five experts said the deal could be approved if Verso agrees to some strategic divestitures, one said antitrust approval would be an “uphill battle,” and another said it could go either way, according to Reuters.

Verso Paper is based in Memphis, Tennessee, and is majority-owned by Apollo Global Management in New York City. It produces 930,000 tons of pulp annually and 1.5 million tons of coated paper and has 2,200 employees nationally, including 1,400 in Maine.

NewPage, which is based in Miamisburg, Ohio, and majority-owned by Los Angeles-based Oaktree Capital Management, produces about 3.5 million tons of coated paper a year and specialty paper used in beverage bottle labels and food packaging. NewPage employs about 5,200 people, with 830 at its Rumford mill.