But the majority opinion written by Justice Ruth Bader Ginsburg stopped short of the tougher restrictions that many in corporate America had sought and left room for legitimate cases by aggrieved investors to proceed, experts said.

"This was something of a victory for investors in that Justice Ginsburg raised the bar but not that high," said Donald Langevoort, a Georgetown University securities law professor.

Typically, plaintiffs can build much of a case in a suit's evidence-discovery phase. But yesterday's ruling, by setting a higher standard for plaintiffs trying to defeat dismissal motions made by defendants, will make it harder to reach the discovery phase.

The decision was the second one this week by the court that was a defeat for shareholders and a victory for the defendant companies. The justices ruled Monday that securities underwriters on Wall Street are generally immune from civil antitrust lawsuits.

Yesterday's decision was hailed by business groups, particularly high-technology companies, which tend to have volatile stock prices and often face lawsuits when their shares unexpectedly tumble.

"Silicon Valley can breathe a sigh of relief," said Jim Hawley, general counsel of TechNet, an industry association that filed a brief with several other technology groups urging the court to set a high hurdle for shareholder lawsuits.

Several class action attorneys also expressed relief, however, saying the court did not endorse a tougher threshold that would have harmed their legal specialization.

The decision "may cut some of the lawsuits, but it won't make a dramatic difference," said Herbert Milstein, a partner at Cohen, Milstein, Hausfeld & Toll in Washington.

The case had been closely watched because it dealt with issues at the center of the debate over so-called frivolous lawsuits filed against companies on behalf of their shareholders.

Business groups claim that attorneys who represent shareholders launch unfounded lawsuits to pressure companies into paying out settlements. Firms say they indeed often feel compelled to settle to avoid the cost of litigation and the risk of eventually losing in court, even if the plaintiffs' case isn't that strong.

Investor advocates counter that fraud occurs more frequently than businesses suggest, as executives seek to maintain high stock prices and enrich themselves, as occurred in the Enron and WorldCom accounting scandals.

The ruling dealt with a lawsuit filed in 2002 against telecommunications equipment maker Tellabs Inc. by investors claiming that executives had publicly promoted the Naperville, Ill., company's outlook when they knew it was worsening.

The case's fate hinged on the legal interpretation of a law passed by Congress in 1995 to reduce securities lawsuits.

The law said plaintiffs must show a "strong inference" of corporate malfeasance for a case to proceed. But lower courts read that guideline in different ways, with some courts being far more hospitable to securities cases than others.

In the Tellabs case, the 7th U.S. Circuit Court of Appeals in Chicago let the suit stand, saying a "reasonable person" could infer that the company had committed fraud.

The high court had been widely expected to adopt a high threshold. The question was how high.

A federal court in Illinois had dismissed the lawsuit, concluding the allegations were too vague and did not raise a "strong inference" that the company intended to deceive shareholders.

The "strong inference" requirement was laid out in a law adopted by Congress in 1995 designed to discourage frivolous securities fraud suits by making it easier for companies to get them thrown out of court.

The Tellabs lawsuit was subsequently reinstated by a U.S. appeals court. The Supreme Court, by an 8-1 vote, ruled the appeals court was wrong, with the majority opinion written by Justice Ruth Bader Ginsburg.

She said that to qualify as strong, an inference must be more than merely plausible or reasonable. It must be cogent and at least as compelling as any opposing inference of nonfraudulent intent, Justice Ginsburg said.

Tellabs had argued that under the 1995 reform law, federal courts must consider any facts that suggest any possible "innocent" motives, and that courts have to dismiss securities fraud cases that don't raise a "strong inference" of intentional wrongdoing.

Tellabs was supported by the U.S. Securities and Exchange Commission and the Justice Department.

Lawyers for the investor plaintiffs had argued that their lawsuit laid out enough specific facts to show that Tellabs knew its best-selling product, a piece of networking equipment known as a cross-connect system, was in decline, but misled investors anyway.

Justice John Paul Stevens dissented, saying he thought it clear that the plaintiffs established probable cause to believe that Mr. Notebaert acted with the required intent.

Ohio State basketball player David Lighty pleaded guilty to a misdemeanor assault charge and was fined $250 in a case involving a jogger who was shot with a BB gun last year.

Two of Lighty’s former teammates at Villa Angela-St. Joseph High School in Cleveland also entered pleas in Cuyahoga County Common Pleas on Tuesday.

Jimmy McLeod and Darryl Rushton each were fined $100 after pleading guilty to disorderly conduct, a minor misdemeanor.

James Nugent, 55, was not seriously hurt last June when he was hit in the back by at least one plastic BB while jogging on the VASJ track. In Cleveland, BB and pellet guns are considered firearms and it is illegal to have them in public places.

Nugent said Tuesday that he had forgiven the 19-year-old defendants and thought the sentences handed down by Judge Kenneth Callahan were fair.

After he was sentenced, Lighty shook Nugent’s hand. Lighty told the judge he wanted to apologize “to Mr. Nugent, to my family, my community and my school.”

Lighty, a 6-foot-5 guard-forward, started seven games last season as the Buckeyes set a school record for victories with a 35-4 record. He was at his best as a defensive specialist who hit some big shots during Ohio State’s run to the national championship game, where the Buckeyes lost to defending champion Florida.

The case deals with alleged industry misconduct during the dot-com bubble of the late 1990s.

The outcome of the antitrust case was vital to Wall Street because damages in antitrust cases are tripled, in contrast to penalties under the securities laws.

The question was whether conduct that is the focus of extensive federal regulation under securities laws is immune from liability under federal antitrust laws.

An antitrust action raises "a substantial risk of injury to the securities market," Justice Stephen Breyer wrote. He said there is "a serious conflict" between applying antitrust law to the case and proper enforcement of the securities law.

In dissent, Justice Clarence Thomas said the securities laws contain language that preserves the right to bring the kind of lawsuit investors filed against the Wall Street investment banks.

In 2005, the 2nd U.S. Circuit Court of Appeals said the conduct alleged in the case is a means of "dangerous manipulation" and that there is no indication Congress contemplated repealing the antitrust laws to protect it.

Investors allege that the investment banks, including Credit Suisse Securities (USA) LLC, agreed to impose illegal tie-ins, or "laddering" arrangements. Favored customers were able to obtain highly sought-after new stock issues in exchange for promises to make subsequent purchases at escalating prices. The investment banks allegedly conspired to levy additional charges for the stock.

As a result of the conspiracy, the investors say, the average price increase on the first day of trading was more than 70 percent in 1999-2000, 8 1/2 times the level from 1981 to 1996.

Private class-action lawsuits, say plaintiffs' attorneys, provide a significant supplement to the limited resources available to the Justice Department to enforce the antitrust laws.

Lawyers for Wall Street investment banks say it is a highly technical matter where the line is drawn between legal and illegal activity in the sale of newly issued stock. It must be left to highly trained securities regulators to decide, rather than to courtroom juries in antitrust lawsuits brought by investors, the industry says.

The Supreme Court concluded that "antitrust courts are likely to make unusually serious mistakes" that hurt defendants. As a result, investment banks must avoid "a wide range of joint conduct that the securities law permits or encourages."

In other action, the court also added one case to its calendar for next term. It will consider whether an investor in a large 401k retirement plan can sue to recover losses to his individual account that are the fault of the plan's manager.

Other Wall Street institutions in the case before the Supreme Court were Bear, Stearns & Co. Inc.; Citigroup Global Markets Inc.; Comerica Inc.; Deutsche Bank Securities Inc.; Fidelity Distributors Corp.; Fidelity Brokerage Services LLC; Fidelity Investments Institutional Services Co. Inc.; Goldman, Sachs & Co.; The Goldman Sachs Group Inc.; Janus Capital Management LLC; Lehman Brothers Inc.; Merrill Lynch, Pierce, Fenner & Smith Inc.; Morgan Stanley & Co. Inc.; Robertson Stephens Inc.; Van Wagoner Capital Management Inc.; and Van Wagoner Funds Inc.

A former Democratic political boss in East St. Louis is facing at least 15 more months in federal prison on environmental infractions -- on top of the 21 months he's already serving in a vote-fraud scheme.

Charles Powell Junior has pleaded guilty in US District Court in East St. Louis to a conspiracy charge and a charge of failing to notify authorities before removing asbestos.

Powell admitted he had been hired to renovate the Spivey Building in East St. Louis and that he had hired another man.

According to court documents, both men knew the building contained asbestos but improperly removed and disposed of asbestos-covered pipes and other asbestos-containing material in 2002. Powell once headed East St. Louis' Democratic Party.