ST. PAUL, Minn. -- Minnesota officials won't be able to investigate whether the Twins or Major League Baseball conspired to compel the state to pay for a new ballpark, the U.S. Supreme Court decided Monday.

The nation's highest court, without comment, denied the state's appeal of a ruling that it could not investigate a possible "taxpayer exploitation conspiracy" despite baseball's exemption from antitrust laws.

Attorney General Mike Hatch, who followed through on the case started by his predecessor, Hubert Humphrey III, was disappointed.

"Our lawsuit sought access to internal baseball documents for the purpose of determining whether they were engaged in illegal, anti-competitive acts," Hatch said.

The Supreme Court created baseball's antitrust exemption in 1922, and in the 1972 Curt Flood case said that it was up to Congress to alter the exemption. The Supreme Court has not accepted a baseball antitrust case since.

"We are obviously pleased with the Supreme Court's action, which upholds what we believe was the correct decision by the Minnesota Supreme Court," said Tom Ostertag, general counsel of the commissioner's office.

Though the decision relieves the Twins of a possible investigation, it does nothing to resolve the team's future in Minnesota, Twins president Jerry Bell said.

The Twins remain in Minneapolis for now, where they have said they can't make enough money in the Metrodome to compete. Their most recent hope for a new stadium collapsed Nov. 2 when St. Paul voters rejected a proposed sales tax increase that would have helped pay for a new stadium there.

"As far as what's next, I don't know," Bell said.

The state attorney general's office began its investigation in 1997 after Twins owner Carl Pohlad announced he would sell the team to a North Carolina partnership if state lawmakers did not authorize public funding for a new ballpark.

Days later, baseball commissioner Bud Selig told Minnesota officials that if a publicly financed stadium was not built, other team owners would approve the Twins' move from Minnesota.

State officials demanded that the Twins and other baseball organizations provide information on the financial viability of the Twins' current stadium, efforts by other teams to get new stadiums and the 1961 move of the Washington Senators to Minnesota.

A Ramsey County District Court judge ordered the Twins to comply with the investigation by providing documents as far back as 1992, but the Minnesota Supreme Court reversed, citing the antitrust exemption and ruling unanimously that neither the Twins nor Major League Baseball could be forced to comply with the investigation.

In the appeal acted on Monday, Hatch argued that the antitrust exemption is narrow enough to allow the state probe.

A broad antitrust exemption would let Major League Baseball "collude among its owners to threaten boycotts of a particular city and extort hundreds of millions of dollars from communities" to pay for new stadiums, the appeal said.

Baseball "is completely unaccountable under the antitrust laws for its behavior" unlike other professional sports, which lack a similar exemption, the appeal added.

The Twins' lawyers urged the court to reject the appeal. They said the exemption applies broadly to the "business of baseball" and has provided stability by keeping teams from moving frequently from one city to another.

Congress deliberately left most of the exemption in place in 1998 when it revoked the antitrust exemption only for labor relations involving the major leagues.

The case is Minnesota vs. Minnesota Twins Partnership, 99-414.