With no progress after more than four years on the Oakland Athletics' planned San Jose move, the city Tuesday filed a federal antitrust lawsuit against Major League Baseball.

The lawsuit argues MLB's decree that the San Francisco Giants have exclusive territorial rights to San Jose, which the defending World Series champions refuse to relinquish, constitutes unlawful restraint of trade.

"For years, MLB has unlawfully conspired to control the location and relocation of major league men's professional baseball clubs under the guise of an 'antitrust exemption' applied to the business of baseball," said the 44-page complaint, filed in U.S. District Court for the Northern District of California in San Jose. The suit, which accuses MLB of a "blatant conspiracy," is being handled at no cost to the city by the Burlingame law firm of Joseph W. Cotchett, which has handled some of the largest antitrust cases in the nation and represented the NFL in similar litigation.

MLB had no comment on the lawsuit Tuesday.

A's owner Lew Wolff said he had "no details" about the lawsuit. He said that "nothing's changed" as far as his team's quest for a San Jose ballpark but added: "I'm not in favor of legal action or legal threats to solve business issues."

Oakland Mayor Jean Quan's office had no immediate comment.

The council vote to sue in a closed session was reported to be unanimous. San Jose Mayor Chuck Reed scheduled an early afternoon news conference. City officials have been discussing the possibility of suing over baseball's monopoly for months. Some have argued that with the A's move to San Jose seemingly stuck in quicksand, and with Baseball Commissioner Bud Selig repeatedly rebuffing the mayor's efforts to move it along, they had little to lose. They have noted other examples in St. Petersburg, Fla., and Seattle where cities eventually got teams after suing baseball.

The suit is a direct challenge to Major League Baseball's unique 91-year-old exemption to federal antitrust laws. It originated with a 1922 U.S. Supreme Court decision that baseball is not interstate commerce subject to federal antitrust regulation. The court twice upheld the decision in 1953 and 1972. Many legal scholars have argued it is inconsistent with law applied to other sports leagues and vulnerable to challenge.

"Whereas baseball may have started as a local affair," the lawsuit said, "modern baseball is squarely within the realm of interstate commerce. MLB Clubs ply their wares nationwide, games are broadcast throughout the country on satellite TV and radio, as well as cable channels, and MLB Clubs have fan bases that span from coast to coast."

But lower court rulings on the exemption since the early 1970s have gone both ways, leaving it unclear how the Supreme Court might rule if it chose to revisit the issue.

"Since the law is so murky, there's no uncontroversial answer," said Stuart Banner, who teaches law at the University of California, Los Angeles and has just written a book, The Baseball Trust, a History of Baseball's Antitrust Exemption. "It all depends on which group of cases you think is more persuasive."

The Giants' territorial rights to the San Jose area originated in the early 1990s. The Giants were considering Santa Clara County for a new stadium to replace frigid, windy Candlestick Park, where they had played since 1960, two years after moving from New York to San Francisco.

Previous A's owners had allowed the territorial reshuffling to accommodate the Giants' move south, farther away from Oakland. After two failed attempts to secure voter approval for taxes to build a new South Bay ballpark, the Giants privately financed AT&T Park in San Francisco, the team's home since 2000.

But the territorial division remained, giving the counties of Marin, San Francisco, San Mateo, Santa Clara, Santa Cruz and Monterey to the Giants, Alameda and Contra Costa to the A's. The two teams disputed the intent of that split in dueling news releases a year ago. The A's argued it was only "subject to relocating" the Giants to Santa Clara County, which the teams had shared when the A's came from Kansas City in 1968. The Giants countered that MLB owners including the A's repeatedly reaffirmed the territorial split, which the Giants relied upon in financing their ballpark.

University of Virginia law professor Gordon Hylton, who has studied the legal history of American sports, said he "never thought that the division of the Bay Area into two distinct areas made much sense." He added that organized baseball's monopoly is "almost certainly a violation of the federal antitrust laws."

But Hylton was skeptical a San Jose antitrust lawsuit against the baseball monopoly would succeed. He argued the Curt Flood Act, signed by President Bill Clinton and named after the St. Louis Cardinals outfielder who lost a 1972 challenge to baseball's monopoly over player contracts in the U.S. Supreme Court, "validated baseball's antitrust exemption in all matters other than major league labor relations."

"San Jose would probably be better off appealing to Congress than the courts," Hylton said.