Companies that operate fantasy sports leagues have a First Amendment right to use players’ names and statistics for free, a court ruled in a case filed against Major League Baseball.

The federal appeals court in St. Louis ruled today in favor of C. B.C. Distribution and Marketing Inc., a closely held operator of fantasy sports leagues.

The ruling is a victory for the fantasy sports business, which started with statistics-rich baseball in 1980 and spread to other sports. Today it is a $1.5 billion industry, according to the Fantasy Sports Trade Association.

“It’s vindication,” said Greg Ambrosius, a former president of the association who is now editor of Fantasy Sports Magazine. “We were a bunch of Mom-and-Pop shops who grew the industry from nothing to where it is today, and then when we got big, people started saying, ‘Hey, we own this.”‘

At issue in the litigation was the right to names and statistics of pro athletes when the information is used by a business rather than a news organization.

“It would be strange law that a person would not have a First Amendment right to use information that is available to everyone,” a three-judge panel said, ruling the Constitution trumps the players’ ability to control their publicity. Major League Baseball’s position in the case was supported in legal briefs by NFL Ventures LP, National Football League Players Association, NBA Properties Inc., NHL Enterprises LP, NASCAR Inc., PGA Tour Inc. and WNBA Enterprises LLC.

Fantasy sports league participants simulate owning professional franchises, complete with scouting, drafting and trading of players. Teams compete based on players’ real-life performance in numerous statistical categories.

Participants pay fees to companies like C.B.C. to track the performance of real players in their imaginary leagues.

Matthew Gould, a spokesman for Major League Baseball Advanced Media, a unit of MLB, declined comment on the ruling. Greg Bouris, a spokesman for the Major League Baseball Players Association, which was also named as a defendant in the suit, didn’t immediately return a voicemail message seeking comment. Baseball fans are passionate about statistics, poring over daily box scores and making data-backed arguments about history’s top batters and pitchers. A survey released in August by the 150- member Fantasy Sports Trade Association said 19.4 million people in America and Canada engage in fantasy sports.

Major League Baseball bought the rights to use player names, photographs and statistics from its players’ union in 2005 for $50 million over five years. MLB sold the annual licensing rights for about $2 million each to companies including CBS Corp.’s SportsLine.com and Walt Disney Co.’s ESPN.