Sotheby Parke Bernet is being sued for $6 million over a candlestick.

It's not just any candlestick. It stands more than five feet high and seems to be made of silver and may have been given by Catherine I of Russia, widow of Peter the Great, to a church in the Kremlin sometime around 1725.

According to a federal court suit filed Monday Philadelphia surgeon Dr. Joseph Sataloff, who had bought the candlestick with some other antiques in this country, offered it to the Smithsonian in 1974. He had it appraised by Botheby's for $130,000. The delighted Smithsonian put it in the Hillwood Museum, where it is on view to this day. Sataloff spread his tax-write-off over four years.

But the Internal Revenue Service decreed, through its own appraisal, that the object was worth no more than $18,000 and disallowed a large part of the deduction. And later the IRS called in a Russian art specialist, Bronislow N. Dvorsky, then at Christie's, the arch-rival of Sotheby's. In 1979 Dvorsky concluded in the appraisal that the candlestick "does not have any artistic or historic significance" and was worth $2,000 to $3,000.

The question was whether the votive object was indeed unique, as the inscription on its flank indicated -- Catherine was supposed to have give a pair of candlesticks to the church, and one had vanished long since -- or merely one of many replicas made over the centuries, complete with inscription. m

The quality of the silver has also come into question.

Sataloff, suffering significant tax liabilities, according to the suit filed in Philadelphia, claims the auction house appraisal was grossly in error. His attorney, Norman Leibovitz, said yesterday the next move up to Sotheby's. Sotheby's attorney Mitchell Zuckerman said there would be no comment and that he had not seen the court papers yet. Dvorsky, now an independent consultant, could not be reached for comment.

Leibovitz said that the $6 million claim covered "lost tax benefits, interest, legal fees, punitive damages . . . and of course emotional trauma."