SUPREME COURT (AP) _ Investors will have a tougher time filing class-action lawsuits that claim companies misled them.


In an 8-to-0 ruling Tuesday the Supreme Court says Merrill Lynch should have been shielded from a lawsuit filed in Oklahoma by former and current brokers. The brokers claim the company released misleading research, which manipulated stock prices.



But the high court says a 1995 federal law prevents the lawsuit.


Justice John Paul Stevens says laws passed after the stock collapse in 1929 ``have anchored federal regulation of vital elements of our economy.''


A Merrill Lynch lawyer says the ruling means public companies no longer have to fear the threat of securities class actions in 50 different states under potentially 50 different sets of laws.