The US Supreme Court on Tuesday dashed the hopes of Enron investors who had brought a $40bn class-action lawsuit against Merrill Lynch and other banks that put together financing deals for the collapsed energy trader.

The investors had tried to persuade the justices to revive their suit, which was blocked by a federal appeals court. The Supreme Court refused to do so, rejecting the appeal in the case, Regents of the University of California v Merrill Lynch, without comment. Legal experts said their action would end the lawsuit. Credit Suisse Group and Barclays were also defendants in the suit, along with other Enron banks.