The real estate advisers who negotiated a 668,000-square-foot headquarters lease for the National Science Foundation may yet win the $6.6 million commission they say they are owed after a ruling Wednesday by a federal appeals panel.

Two years ago, the real estate services firm JLL negotiated a 15-year lease with the federal government for the NSF to move its headquarters from Ballston to the Eisenhower Avenue area of Alexandria.

There the agency will anchor a 56-acre development called Hoffman Town Center, named for the Hoffman family, owner and developer of the project.

Once the deal was inked, however, the client — Hoffman Family LLC — and its advisers almost immediately disagreed over what JLL’s team was owed for its work. JLL said the commission was a little over $6.6 million, or 2 percent of the $330 million lease.

Representatives for the Hoffman family argued in court that it owed only $1 million in part because one member of the JLL team, Arthur M. Turowski, was not eligible for a commission because he was not a licensed broker.

Last year a judge in U.S. District Court in Alexandria agreed with the family, but JLL appealed and won a unanimous opinion Wednesday  from a three-judge panel of the U.S. Court of Appeals for the 4th Circuit in Richmond.

Although Judge Allyson K. Duncan acknowledged in her ruling that Turowski was not a licensed broker in Virginia, she and the other judges disagreed with the lower court’s ruling that Hoffman was within its rights not to pay the brokerage fees.

“Hoffman can point to no authority under Virginia law that would compel a forfeiture of JLL’s commission under the circumstances presented here,” Duncan wrote.

The ruling means that barring a settlement, the case is likely headed to a jury.

A spokeswoman for JLL, Mittie Rooney, said the company was “looking forward to resolving this matter at the district court” and was “committed to getting great results for our clients as we did for the Hoffman family with the National Science Foundation lease.”

JLL’s attorney, Stephen M. Sayers of Hunton & Williams, said he expected to see the court set a jury trial date soon. “We were absolutely pleased that the court ruled JLL’s way and it didn’t appear to be a particularity close case,”  he said.

An attorney for Hoffman Family LLC did not return a request seeking comment.

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