After a monthslong process that saw two high-powered conglomerates slugging it out to manage the construction of a new terminal for Louis Armstrong International Airport, a winner finally emerged Thursday as the New Orleans Aviation Board unanimously upheld the recommendation that a group including some regional construction powerhouses said should get the contract.

But it remains to be seen whether the board’s selection of Hunt Gibbs Boh Metro represents the final word on the matter or whether NOLA Airport Builders, a competing joint venture that has formally challenged the scoring that ranked it second, will take the fight to the courts.

An attorney for NOLA Airport Builders hinted at the possibility of a lawsuit Thursday when he made the case for the board to throw out the scoring that ranked his clients second. But the Aviation Board, after hearing from both bidders and discussing the issue in a closed-door executive session, said the complaints raised by NOLA Airport Builders did not rise to the level of improprieties that would justify overruling the committee that evaluated both proposals or restarting the process once again.

“This has been a very long process for all of us, and all of us are ready to move and build a world-class airport,” board member Doug Thornton said before the votes were cast.

“It’s not a public bid. The test really has to be that the committee acted in an arbitrary or capricious manner or abused discretion, and I don’t see where that occurred in this case,” said Thornton, an executive vice president with SMG, the company that manages the Mercedes-Benz Superdome and Smoothie King Arena.

Hunt Gibbs Boh Metro came out on top this month when the most recent proposals from both joint ventures were scored by an evaluation committee. Hunt Gibbs is a partnership between Indianapolis-based Hunt Construction and three local companies: Gibbs Construction, Boh Bros. Construction and Metro Services Group.

But NOLA Airport Builders, made up of California-based Parsons Corp., the Brazilian firm Odebrecht and New Orleans-based Royal Engineers, argued in its protest that the committee’s scoring was incorrect.

The issue seemed to boil down to whether the evaluation committee was bound by objective requirements and criteria or whether members could use their own judgment when rating the two proposals.

In his presentation to the Aviation Board, James Moye, an attorney for NOLA Airport Builders, argued that Hunt Gibbs Boh Metro did not fulfill some requirements laid out in the request for proposals that outlined the requirements for bidding on the project. That included having certain qualifications for some members of each joint venture.

Moye also argued that Metro Services did not have the proper certifications to show that it qualifies as a “disadvantaged business enterprise” for construction management services. Metro’s certification as a minority-owned business also was called into question in an earlier round of evaluations because it had used a different procedure from the one specified by the airport.

Moye said the NOLA Airport Builders proposal also presented the airport with more value for its money and a higher participation rate by DBE firms — those owned by minorities or women — yet the evaluation committee did not score it as highly in those categories as it did Hunt Gibbs Boh Metro.

In response, Hunt Gibbs attorney Daniel Lund III argued that the evaluation committee was allowed to use its discretion when scoring the proposals. In addition, he said, the very requirements that Moye said the Hunt Gibbs proposal violated also had not been met by NOLA Airport Builders.

Ironically, those philosophical positions were reversed just a few months ago, when Hunt Gibbs Boh Metro lodged a protest against a previous evaluation committee’s recommendation that the Aviation Board select Parsons-Odebrecht, the forerunner to NOLA Airport Builders. That recommendation came after both firms had tied in an initial scoring round.

At that time, Hunt Gibbs Boh Metro argued that the evaluation committee should have used objective criteria when evaluating the proposals. Had that happened, there would have been no need for a tie-breaking second round of voting, according to its protest.

Lund did not spend a significant amount of time addressing the claims about Metro, which were raised only during the debate in front of the Aviation Board and not included in NOLA Airport Builders’ formal protest. However, he said the company had the proper certifications as a DBE.

Board members would not comment Thursday on the reasons they rejected NOLA Airport Builders’ challenge or why they chose to stand by the evaluation committee’s recommendation even though, when presented with a challenge to the prior evaluations, the board that time opted to throw out the whole process and start from scratch.

However, the latest set of evaluations was not marred by some issues that cropped up in the previous round. In addition to the peculiarities brought about by the tie in the scoring, those evaluations also were questioned after attention was drawn to an evaluation committee member’s prior work for Parsons and to a past claim of discrimination against one of the contractors for Parsons-Odebrecht.

Airport officials now will begin to negotiate a contract with Hunt Gibbs Boh Metro. When that is complete, the joint venture will begin working on pre-construction services, a process that is expected to take about 10 months.

The contractor and the airport will agree on a figure known as a “guaranteed maximum price,” essentially the final budget for the project. The contractor will be responsible for ensuring the terminal comes in within that budget, and it will be held responsible for covering any cost overruns.

The goal remains to have the terminal completed by May 2018 so that it can be opened during the city’s tricentennial year.

That, of course, could be held up should NOLA Airport Builders file a lawsuit to challenge the board’s decision.

While a lawsuit was a possibility regardless of what the Aviation Board decided, Moye argued that siding with NOLA Airport Builders would have given the board the strongest chance to win the case.

“You can defend that lawsuit. I don’t know how you’ll defend ours,” he said.

Follow Jeff Adelson on Twitter, @jadelson.