The company also gained cooperating rights to Segra Field, a 5,000-seat venue owned by DC United, a person familiar with the deal said.
Terms were not disclosed and it is unclear how much ownership stake DC United retains in the Leesburg team.
In a statement, Baroni said he looks forward to “building on the momentum that [D.C. United chief executive] Jason Levien and the team have created. I have a tremendous passion for the sport of soccer and am committed to working together to enhance the fan experience and continue to strengthen the connection to the Northern Virginia community.
Loudoun United competes in the 25-team United Soccer League Championship, which is one level below MLS. Prioritizing player development over competitive record, the team has never qualified for the playoffs and averaged about 1,500 fans last year. The 34-game schedule this season will begin on March 11.
“We are extremely proud of what we have achieved with the club and are confident that the sale and introduction of Greg Baroni and Attain Sports and Entertainment into the ownership group will take us to new heights,” Levin said in a statement.
DC United saw Baroni’s business connections — he founded consulting and private equity firms and chairs the Northern Virginia Technology Council — as a way to better monetize Segra Field. Besides Loudoun United, the stadium is home to Old Glory DC, a pro rugby team, but does not stage many other events.
The NWSL’s Washington Spirit will no longer play at Segra Field, instead scheduling all home dates at Audi Field, the 20,000-capacity venue in the district that is owned by DC United.
Loudoun’s ownership change comes as MLS and the USL ramp down their relationship. For player development purposes, MLS organizations for years have had a majority ownership stake or affiliation with clubs in the USL Championship or USL League One, a third division circuit.
Last year, however, MLS largely focused on nurturing players by launching a third-division league, MLS Next Pro. DC United continued to operate Loudoun United in the USL Championship but, in the long term, it is planning to launch an MLS Next Pro team in greater Baltimore within a few years.
With greater independence, Loudoun United is eligible to compete in the US.