New York-based Soros Fund Management LLC will have to pay a fine of 489 million forints ($2.5 million) for unlawful trades in shares of OTP Bank , market regulator PSZAF said.
PSZAF said on Friday a Hungarian court rejected an appeal in a final ruling against the fine handed out in March 2009.
The fine related to a complicated series of deals just before the market closed on October 9, 2008, which PSZAF said improperly influenced the market and led to a plunge in the price of the shares of the country's biggest bank.
The deals were struck in a period when Hungary's financial and capital markets were roiled by the global crisis, and affected a stock that heavily influences Hungary's BUX <.BUX> equity index, PSZAF said last year.
In October 2008 Hungary became the first European Union member forced to turn for aid to the International Monetary Fund.
Soros Fund Management LLC was founded by Hungarian-born businessman George Soros.
(Reporting by Sandor Peto, editing by Will Waterman)