Barclays Plc is not liable to investors who bought its U.S.-listed stock a few months before the 2008 financial crisis and accused the British bank of hiding its risky debt exposure and a capital shortfall, a U.S. court ruled on Monday.

In a 3-0 decision, the 2nd U.S. Circuit Court of Appeals in Manhattan upheld the dismissal of claims against Barclays and underwriters led by Citigroup Inc over the British bank's April 2008 sale of $2.5 billion of American depositary shares. Barclays' share price had fallen 80 percent by the following March.

The 9-1/2-year-old case is among the last ones accusing big banks of having inflated their share prices by hiding or failing to fix soured credits on their balance sheets before the crisis.

Barclays was accused of concealing 21.6 billion pounds (then about US$42 billion) of mortgage-backed securities and other risky assets insured by monoline insurers, and a March 2008 "directive" by the U.K. Financial Services Authority requiring it to raise more equity capital.

Barclays might have had a duty to disclose its monoline exposure, but "resoundingly" showed that its omission had little or no impact on its share price, the appeals court said.

A regulator's "expressions of concerns about a bank's financial status and vigorous requests - even if expressed urgently - to be kept apprised of the bank's contingency plans" did not qualify as a "directive," the court ruled.

Joseph Daley, a lawyer for the plaintiffs, did not immediately respond to requests for comment. Barclays spokesman Andrew Smith declined to comment.

The decision on Monday affirmed a September 2017 ruling by U.S. District Judge Paul Crotty in Manhattan.

Crotty said the collapse of Lehman Brothers Holdings Inc., the bailout of insurer American International Group Inc., and capital raisings by other British banks might also have contributed to Barclays' falling share price.

The case is In re: Barclays Bank Plc Securities Litigation, 2nd U.S. Circuit Court of Appeals, No. 17-3293.