The planned $1.9 billion merger between Alaska Airlines and Hawaiian Airlines moved a step closer to completion on Monday with the expiration of the U.S. Department of Justice’s allowed time period to complete its investigation of the deal and, if warranted, initiate legal action to block it.

In a statement released shortly after the deadline passed, Alaska called the expiration a “significant milestone in the process to join our airlines.”

The deadline passed without comment from either the DOJ or the U.S. Department of Transportation.

Alaska’s acquisition of Hawaiian remains subject to the DOT approving an interim exemption application.

“Following that step, we will complete work to close the transaction, and proceed with integrating the two companies, welcoming Hawaiian Airlines guests and employees into Alaska Air Group, and expanding benefits and choice for consumers throughout Hawaii, the Asia-Pacific region, continental United States and globally,” the airline stated in its release.

If the deal goes through, it would be the largest merger of U.S. carriers since Alaska merged with Virgin America in 2016.

The two airlines announced the proposed merger in December 2023 but even then there was recognition that the deal could be subject to an antitrust suit.

Last year, a federal judge agreed with the DOJ’s contention that the Northeast Alliance partnership forged between American Airlines and JetBlue — which allowed for codesharing and transferable loyalty benefits on flights in and out of New York and Boston — unfairly stymied competition. The decision led to the dissolution of the program.

In January, the DOJ again prevailed in blocking JetBlue Airways from acquiring Spirit Airlines, citing antitrust concerns.

“During the DOJ’s review, Alaska worked closely with the Hawaii attorney general to reinforce and expand upon our commitments for the future of Hawaiian Airlines and to Hawaii consumers,” the Alaska statement read. “These include plans to maintain the Hawaiian Airlines brand and local jobs and continue providing strong service between, to, and from the Islands.”

Gov. Josh Green said his administration worked with Alaska officials over the past several months to review potential impacts and insisted that any changes expand travel options for Hawaii residents and preserve union jobs.

“Alaska has reinforced commitments to our state and will maintain the Hawaiian Airlines brand, preserve and grow union jobs in our Hawaii, as well as continue to provide crucial passenger and air cargo service to, from, and within the islands,” Green said in a statement released on Monday. “The merger will vastly expand the number of destinations throughout North America for Hawaii residents that can be reached nonstop or one-stop from the islands, and HawaiianMiles members will retain the value of their miles while gaining access to more destinations around the world,” Green said.

“I am confident that by the joining of these two airlines, a stronger company will emerge and offer more travel options for Hawaii residents and local businesses and will enhance competition across the U.S. airline industry.”

Green said he appreciated the DOJ’s “strong consideration of Hawaii’s unique needs.”

“I look forward to this merger proceeding and the overwhelming consumer, employee and community benefits that will result from it,” he said.

Michael Tsai covers local and state politics for Spectrum News Hawaii. He can be reached at michael.tsai@charter.com.