WASHINGTON — Investors are heading into 2008 stung by a series of legal and regulatory setbacks, analysts say, with the latest the Supreme Court's ruling protecting businesses from securities-fraud lawsuits.

Yesterday's ruling follows a decision late last year by regulators allowing companies to deny shareholders access to annual director-election ballots, and comes amid share dilution and dividend cuts at big banks stung by the mortgage crisis.

"It's not a good time," lamented Barbara Roper, director of investor protection at Consumer Federation of America.

As the stunning corporate scandals of 2002 recede from memory, Roper and other investor advocates say that recent developments in courtrooms, federal agencies and corporate boardrooms have eroded the interests and protection of Main Street shareholders.

"It's like Enron and WorldCom never happened," Roper said.

James Cox, a professor at Duke University who specializes in securities law, said that investors "are seeing a piling-on."

The Securities and Exchange Commission in November drew the ire of governance advocates and big shareholders like pension funds when its commissioners voted 3-1 to let companies deny investors access to public companies' annual proxy ballots.

SEC Chairman Christopher Cox has said the shareholder-rights rule was needed to provide clarity before the corporate proxy season begins. But critics say the move could make corporate America less responsive to investors.

Investors also have suffered from reduced dividends and diluted share value by investment banks that lost big on mortgage securities.

In the case before the Supreme Court, the justices ruled yesterday against investors who alleged that two suppliers of cable TV set-top boxes, Scientific-Atlanta and Motorola, colluded with Charter Communications Inc. to deceive Charter's stockholders and inflate the price of the cable TV company's stock.

The decision is expected to have an impact on a similar class-action lawsuit by shareholders in scandal-ridden Enron Corp. Investors in Enron, once the nation's seventh-largest company, are seeking more than $30 billion from investment banks, alleging they colluded with Enron to mask its financial problems.