(Reuters) - A federal appeals court on Monday said professional minor league baseball is exempt from U.S. antitrust laws, and rejected an appeal by players who complained that their wages were kept artificially low.

Sep 19, 2016; Port St. Lucie, FL, USA; A detailed view of the batting helmet and baseball bats of New York Mets outfielder Tim Tebow (15) during his workout at the Mets Minor League Complex. Jasen Vinlove-USA TODAY Sports

By a 3-0 vote, the 9th U.S. Circuit Court of Appeals in San Francisco said minor league baseball falls “squarely” within the “business-of-baseball” antitrust exemption that the U.S. Supreme Court granted the sport in 1922.

“The employment contracts of minor league players relate to the business of providing public baseball games for profit between clubs of professional baseball players,” Chief Judge Sidney Thomas wrote for the appeals court panel.

Monday’s decision is a defeat for four plaintiffs who played minor league baseball at some point between 2010 and 2012.

They brought class-action claims accusing Major League Baseball and its 30 teams of suppressing wages, leaving most minor leaguers earning between $3,000 and $7,500 annually, and nothing during spring training.

In contrast, the minimum salary for major leaguers is $535,000.

Samuel Kornhauser, a lawyer for the plaintiffs, said his clients will likely ask the 9th Circuit to reconsider its decision, or appeal to the U.S. Supreme Court.

“Obviously, we think it’s wrong, and that the ‘business of baseball’ is a lot different today than it was in 1922,” he said in an interview. “There is no reason minor leaguers should not have the right to negotiate for a competitive wage.”

Matt Bourne, a spokesman for Major League Baseball, declined to comment.

The players claimed that Major League Baseball exercised unwarranted control primarily through a “reserve clause” that lets teams retain players’ rights for seven years.

Thomas, however, said the U.S. Congress “has made clear its intent to maintain the baseball exemption for anything related to the employment of minor league players.”

He said this in part reflected the 1998 passage of the Curt Flood Act, named for the former St. Louis Cardinals outfielder who unsuccessfully challenged Major League Baseball’s reserve clause.

Monday’s decision upheld a Sept. 2015 dismissal by U.S. District Judge Haywood Gilliam in Oakland, California.

The case is Miranda et al v Selig et al, 9th U.S. Circuit Court of Appeals, No. 15-16938.