NEW YORK, Nov 13 (Reuters) - A U.S. appeals court on

Wednesday threw out a $1.68 billion judgment against Iran's

central bank that had been won by family members of troops

killed and injured in the 1983 bombing of the U.S. Marine Corps

barracks in Beirut.

The 2nd U.S. Circuit Court of Appeals in Manhattan said a

lower court judge should have addressed questions of state law

before ruling against Bank Markazi and Luxembourg intermediary

Clearstream Banking, a unit of Deutsche Boerse.

In a 3-0 decision, the panel also rejected a claim that a

2019 federal law designed to make it easier to seize Iranian

assets held outside the United States waived Bank Markazi's

sovereign immunity.

That law "neither abrogates Bank Markazi's jurisdictional

immunity nor provides an independent grant of subject matter

jurisdiction," Circuit Judge Robert Sack wrote.

The court returned the case to U.S. District Loretta Preska

in Manhattan to address state law questions in the 11-year-old

case, and whether the case can proceed at all in Bank Markazi's

absence.

Bombing victims sought to hold Iran liable for providing

material support for the Oct. 23, 1983, suicide attack that

killed 241 U.S. service members, by seizing bond proceeds held

by Clearstream in a blocked account on Bank Markazi's behalf.

Bank Markazi claimed immunity under the Foreign Sovereign

Immunities Act, which generally shields foreign governments from

liability in U.S. courts.

Lawyers for the plaintiffs did not immediately respond to

requests for comment. Bank Markazi's and Clearstream's lawyers

did not immediately respond to similar requests.

Iran, other U.S.-designated sponsors of terrorism, and banks

accused of providing services to terrorists face thousands of

claims in U.S. courts by victims and their families. It is often

difficult for these claimants to collect judgments.

In the Bank Markazi case, the plaintiffs sued in 2013 to

partially satisfy a $2.65 billion default judgment they had won

against Iran in 2007.

Another judge dismissed the case in 2015, but the 2nd

Circuit revived it in 2017.

Then in 2020, the U.S. Supreme Court ordered a fresh review

in light of the 2019 law, which then-President Donald Trump

signed as part of the National Defense Authorization Act.

The plaintiffs have said they hold more than $4 billion of

judgments against Iran and have been unable to collect for

decades.

The case is Peterson et al v. Bank Markazi et al, 2nd U.S.

Circuit Court of Appeals, No. 15-690.