(FORTUNE Magazine) – With accusations of collusion and threats of a strike, the wide world of sports looks more like an industrial battleground every day. Baseball is anxiously awaiting a ruling by arbitrator Thomas Roberts that could alter the game's economic power structure. He is to decide September 21 whether major league owners conspired after the 1985 season to refrain from bidding against one another for players. Since an arbitrator's 1975 decision enabled players to offer their services on the open market, owners have shelled out millions to get the best.

But the wild spending stopped after Peter Ueberroth became Baseball Commissioner in 1984. He derided the owners for their lavish spending and urged them to cease, which they did. Even New York Yankee owner George Steinbrenner, who used to brag about how much he spent on players, shut his wallet. Only two superstar free agents have changed teams in the past two years -- catcher Lance Parrish went from Detroit to Philadelphia and outfielder Andre Dawson from Montreal to the Chicago Cubs -- while other independent-minded players didn't even get more than one offer. Such sudden cohesiveness among egotistical owners did not look like coincidence to the players. Says Donald Fehr, head of the players' union: ''The clubs rigged the market.'' If the players win, the owners could be liable for millions of dollars in damages and compensation. Labor relations aren't much smoother in pro football. The collective- bargaini ng agreement reached after a strike in 1982 expired at the end of August. Once-polite talks are turning acrimonious, and another strike seems possible. Observes Jack Donlan of the National Football League management council and the owners' chief negotiator: ''It took us almost three years to get back the momentum we had before the last strike.''