A federal judge has ruled in favor of the Justice Department (DOJ) and the attorneys general of six states and the District of Columbia in an antitrust lawsuit to stop the Northeast Alliance between American Airlines and JetBlue Airways.

Attorney General Merrick B. Garland and Assistant Attorney General Jonathan Kanter for the Justice Department’s Antitrust Division issued a statement in support of the ruling on May 19 after a judge from the the U.S. District Court for Massachusetts ruled in favor of the Justice Department, issuing a special injuction to stop the implementation of the merger.

"We are pleased with the court's decision," the two wrote in a statement published by the DOJ. "The outcome of this litigation recognizes the value of competition in the airline industry. We are grateful to our state law enforcement partners and the dedicated and talented Antitrust Division staff that investigated and tried this important case.”

The decision came after the DOJ raised concerns about potential antitrust violations resulting from the partnership, as well as a trial that began in September and spanned several weeks. According to the court's ruling, the partnership between JetBlue and American violated Section 1 of the Sherman Act. The court determined that both companies had entered into an agreement that resulted in the cessation of competitive pricing in crucial markets, the release added. According to the ruling, collusion by JetBlue and American to stop competing in Boston and New York, where both carriers were major players, violated the Sherman Act because it increased fares and reduced choice for American travelers in many domestic markets for scheduled air passenger service.

"Today's decision is a win for Americans who rely on competition between airlines to travel affordably," Garland said in his statement. "The Justice Department will continue to protect competition and enforce our antitrust laws in the heavily consolidated airline industry and across every industry."