Two weeks have passed since the proposed $1.9 billion merger between competitors Alaska Airlines and Hawaiian Airlines cleared what is traditionally considered its most significant regulatory hurdle. Now what?

The U.S. Department of Justice’s formal review period for the proposed merger under the Hart-Scott-Rodino Act expired quietly at 12:01 a.m. Eastern time Aug 19. It was almost anticlimactic given the heightened tension and speculation after the review period, originally slated to end Aug. 5, was extended three times.

But a spokesperson for Alaska Airlines said in a statement this week, “While the HSR Act waiting period has expired, satisfying one of the necessary conditions to close, the proposed combination of Alaska Airlines and Hawaiian Airlines remains subject to the U.S. Department of Transportation (DOT) approving an interim exemption application for the transfer of international route authorities. USDOT’s review of this interim exemption application has not yet been concluded.”

The Justice Department enforces Section 7 of the Clayton Act, which prohibits mergers and acquisitions that could substantially lessen competition or create a monopoly. However, the DOT, which once had the primary responsibility for reviewing airline mergers, still retains the power to deny requests to exempt international airline agreements from the antitrust laws, which is the last required step before Alaska and Hawaiian can combine.

A U.S. DOT spokesperson said in a statement Thursday, “Alaska Airlines and Hawaiian Airlines have filed a transfer application to combine under one certificate and cannot combine their operating authorities without the U.S. Department of Transportation’s approval. The Department is reviewing the application and can only approve a transfer if it is in the public interest.”

Transportation officials declined further comment, but a key difference is that their review period is not subject to a published timetable like the DOJ’s review, which was assigned an expiration date.

The Association of Flight Attendants-CWA said in a Aug. 19 news release that DOT’s authority to review international routes and the merger’s general compliance with DOT requirements “has typically been a perfunctory approval.”

But aviation historian Peter Forman says it can take a few months for the DOT to finish scrutinizing the deal, which he thinks will clear regulatory hurdles.

While the DOT has taken a less deferential position to the Justice Department under the Biden administration, Forman said, “I’m just not seeing a history of the DOT standing in the way of a merger. The DOJ has always taken the lead since 1989. I just really don’t anticipate problems here.”

Forman said when he looks at Wall Street, it doesn’t appear that Hawaiian’s investors feel shaky about the deal either, as the stock price was $17.32 a share Friday. Alaska said it would pay $18 a share in cash as part of the deal.

“We are close enough to $18 a share that the Hawaiian investors feel that this thing is going to go through,” he said. “Prior to the DOJ decision, it wasn’t nearly that high, so there’s a big confidence increase after the DOJ decision, and not much has happened since then; it’s still very high.”

There is potentially a lot riding on the merger, given Hawaiian’s financial challenges now and over the past several years. Hawaiian reported a second-quarter net loss of $1.30 a share, or $67.6 million, as compared with a $12.3 million net loss a year ago. When adjusted for nonrecurring costs, the second-­quarter loss came to $1.37 a share.

The uncertain timing of the DOT decision has made some community members nervous and has raised concerns that a delay could have hurt Hawaiian’s already strained financial performance, as well as workforce retention and quality of life for Hawaiian’s 7,400 workers.

Hawaiian and Alaska must remain competitors until the regulatory process is completed for their proposed merger agreement, which was entered into Dec. 2 after the boards of directors for both air carriers approved the deal.

There is broad support for the merger, which would turn Alaska into the fifth- largest U.S. airline behind American, Delta, Southwest and United airlines, which together control about 80% of the U.S. airline market.

Forman said, “I’ve been arguing that creating a medium-sized airline is actually pro-competition because now you have an airline that is more capable of competing with the ‘Big 4.’ I think the DOJ kind of saw that, too. This is going to leave a more competitive environment rather than a less competitive environment.”

United Airlines officials, however, have expressed concern that the combination would hurt their business. The Transportation Department posted a note to its case docket saying that Robert Rivkin, United’s senior vice president and chief legal officer, on Aug. 27 expressed concerns on the merger’s potential impact to United’s “interline, codeshare, special prorate, and loyalty agreements with Hawaiian Airlines.”

A motion is pending for Chief U.S. District Judge Derrick Watson to reconsider his Aug. 12 dismissal of a lawsuit that sought to block Alaska Airlines’ plan to buy Hawaiian Airlines on the grounds that the merger would result in higher fares, job losses and fewer flights, and cause injury to Hawaii’s economy.

The suit was filed in April on behalf of eight passengers: Warren Yoshimoto, Kristin Barroga, Sean Kett­ley, Carolyn Fjord, Don Freeland, Don Fry, Bill Rubinsohn and Clyde Stensrud. The passengers, including three Hawaii residents, were represented by antitrust attorney Joseph Alioto and Tatiana Wallace of the Alioto Law Firm in San Francisco, and Terence O’Toole, Andy Lautenbach and Kukui Claydon of the Starn, O’Toole, Marcus and Fisher law firm in Honolulu.

Alioto told the Honolulu Star-Advertiser, “The judge was of the view that plaintiffs did not have standing. We filed affidavits demonstrating that plaintiffs flew often in all markets.”

Support has come from Washington Gov. Jay Inslee, Oregon Gov. Tina Kotek and Hawaii Gov. Josh Green, who sent a letter to USDOT in strong support of the merger, and on Friday he added, “I continue to advocate for our state at the highest levels.”

In a statement issued Aug. 19, Green said he and his administration have worked over the past few months with Alaska’s leadership to satisfy concerns about potential impacts.

“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,” he said.

A DOT docket note dated Friday indicates that state Attorney General Anne E. Lopez spoke with Mohsin Syed, Transportation Secretary Pete Buttigieg’s chief of staff, and Brian Stansbury, DOT deputy general counsel, about the commitments made by Alaska Airlines for the future of Hawaiian Airlines and to Hawaii consumers.

The docket note said, “Attorney General Lopez stressed the importance of protecting the interests of the people of Hawaii in connection with this merger,” and stated that Lopez shared some observations and concerns, including:

>> The role affordable interisland travel plays in the lives of (Hawaii residents), including access to health care, advancing education, connecting families and moving cargo.

>> The importance of preserving interisland flights at an affordable price.

>> The concern that Alaska Airlines would repurpose Hawaiian Airlines Airbus jets and use them to replace Boeing jets on routes that do not serve Hawaii.

The conversation shows that the Transportation Department is taking a close look and is even going beyond submittals.

Most of the submittals in the file are in support, and a host are from airline labor unions.

Capt. Larry Payne, chair of Air Line Pilots Association International Hawaiian Airlines, said in a statement Thursday, “After careful evaluation, and if executed properly, we believe that the merger between Hawaiian Airlines and Alaska Airlines is not only beneficial for our combined pilot group of 4,600 unionized pilots, it also serves in the best interests of our passengers and Hawaiian communities.”

On Wednesday the International Association of Machinists and Aerospace Workers announced support for the merger. The union highlighted the existing collective bargaining agreements with both airlines, which ensure job security, competitive pay and industry-leading health care for IAM members.

In an Aug. 9 letter to DOT, the Association of Flight Attendants-CWA also urged the Transportation Department to approve the merger “so that Flight Attendants, other workers, and consumers can access the benefits of the merger as soon as possible.”

The Aircraft Mechanics Fraternal Association said in a letter, “Together, the combined carrier will have a larger and more diverse fleet, bringing additional jobs and opportunities for our members. The combination will enhance our ability to continue to compete, support employee careers, and grow labor-represented jobs across the network.”

Transportation officials are not saying how this feedback is influencing its review, or even how much more analysis is planned. The federal agency was once seen as softer on mergers, but not now with the Biden administration.

“This administration wants to make it abundantly clear that they are more concerned with the consumers than with the airlines themselves,” Forman said.