By Elena Fabrichnaya

MOSCOW (Reuters) - Raiffeisen Bank International (RBI) said it plans another appeal after a Russian court on Thursday upheld an earlier ruling that it must pay over 2 billion euros ($2.28 billion) in damages over a collapsed investment deal.

Austria's RBI was ordered to pay the money to Russian investment company Rasperia in a landmark ruling in January that was one of the harshest against a Western company still doing business in Russia. It is the biggest Western bank still operating there.

A court in St Petersburg on Thursday rejected RBI's appeal, saying the original decision was unchanged and the bank's complaint was not satisfied.

Alongside its next appeal, RBI said in a statement it was also preparing a separate claim against Rasperia to be filed in Austria in the second quarter of this year.

RBI has around 6 billion euros in Russia, earned from international payments and on billions of euros in Russian deposits, a person with knowledge of the matter has told Reuters.

The bank's dispute with Rasperia followed the failure of a deal that RBI hoped would allow it to unlock some of those frozen billions. RBI had sought to buy a stake in Vienna-based construction company Strabag, but pulled out under pressure from Washington.

U.S. officials long suspected that sanctioned Russian tycoon Oleg Deripaska would benefit from the sale, sources have told Reuters. After the deal was dropped the U.S. Treasury imposed sanctions on a web of Russian companies, saying they had been used to disguise ownership. Deripaska has repeatedly denied any connection.

In February, Raiffeisen CEO Johann Strobl said the bank was "very, very confident" it would win an Austrian case to claim Rasperia's roughly 1.2 billion euros in assets in Austria if the Russian damages ruling was confirmed.

RBI said it expects no additional financial impact from Thursday's verdict beyond the 840 million euro provision already made by its Russian unit. That sum reflects the amount of Russian damages minus what it could recover in Austria.

CITIBANK CASE

In a victory for a Western bank in a separate case, Russia's Supreme Court on Wednesday overturned all previous decisions in a dispute involving the Russian unit of Citibank, which Russia's Sovcombank is suing for $24 million over an alleged debt owed by its U.S. parent, and ordered a new trial in the Moscow Arbitration Court. Raiffeisen's lawyers said they interpreted that decision as a precedent meaning that a Russian subsidiary of a foreign company could not be held liable for the debts of its parent. Andrei Timchuk of law firm Delcredere, representing Raiffeisen, told Reuters that he had sought a postponement of Thursday's ruling so that the Supreme Court ruling in the Citibank case could be taken into account, but the request was denied. "It is completely unclear why the court ignored the position of the Supreme Court," he said. Rasperia's lawyer Igor Ozersky expressed satisfaction with Thursday's decision. He told Reuters the Citibank dispute involved "different circumstances" and was in no way connected with the Raiffeisen case. Both lawyers said Thursday's decision meant the court ruling against Raiffeisen was now in force and it would have to pay the 2 billion euros.

($1 = 0.8790 euros)

(Additional reporting by Rachel More in Berlin; writing by Mark Trevelyan; Editing by Susan Fenton)