A federal grand jury in New York yesterday returned the largest tax-evasion indictment in U.S. history, charging the giant Swiss trading firm Marc Rich & Co. AG and its chairman, Marc Rich, with using sham oil transactions in 1980 and 1981 to escape more than $48 million in U.S. taxes.

The 51-count indictment, which also named the U.S. subsidiary of the giant trading company and two of Marc Rich's associates, said that the defendants concealed more than $100 million in taxable income from federal authorities.

The grand jury also charged Marc Rich himself and his long-time associate, Pincus Green, with illegally buying more than $200 million worth of oil from Iran after President Jimmy Carter banned trade with that nation during the hostage crisis. It was not immediately clear to whom Rich allegedly sold the oil.

Assistant U.S. Attorney Morris Weinberg, who was in charge of the case, said Rich and Green used unnamed U.S. banks that unwittingly transferred funds from the United States that eventually ended up in the hands of the National Iranian Oil Co.

The Rich companies, Rich, Green and another associate, Clyde Meltzer, were charged under the Racketeer Influenced and Corrupt Organization law. Manhattan U.S. Attorney Rudolph Giuliani said that under the RICO statute, the government will seek to confiscate several hundred million dollars of stock in the Swiss trading firm that is owned by Rich himself and Green.

The Swiss firm is reported to have revenue of between $10 billion and $15 billion a year.

Weinberg said that Rich's personal and corporate assets in the United States exceed $100 million, including part ownership of 20th Century-Fox, the big movie production company. Court orders have been issued to prevent the sale or transfer of Rich assets.

Meltzer is in New York, but Rich and Green, both 49, fled last June to company headquarters in Zug, a tiny Swiss village near Zurich. Neither Rich nor Green can be tried in absentia, the U.S. Attorney's Office said, and warrants have been issued for their arrests.

Giuliani said that Rich, a Belgian-born U.S. citizen, has attempted to renounce his citizenship to become a Spanish citizen. Rich maintains a residence in Spain.

According to the indictment, the U.S. subsidiary purchased oil at a substantial loss from the Swiss parent in order to transfer profits from the United States to Switzerland.

The U.S. subsidiary--called Marc Rich International Ltd. until it was secretly sold in late June to associates of Rich--supplied documents subpoenaed by the grand jury, but the Swiss parent resisted.

Marc Rich's motivation in resisting the subpoenas was to protect the privacy of clients involved in the commodity transactions his firm handles, according to reports of meetings Rich and some of his associates had with Swiss journalists last week. Rich and his associates described themselves as go-betweens in trading between countries that do not communicate with each other directly. Although Rich apparently did not identify any of the countries, sources said the firm has shipped crude oil from Soviet Bloc nations to South Africa, and from Iran to the United States and Europe during the Iranian embargo.

Last month, under the pressure of a $50,000-a-day fine imposed June 29 by U.S. District Judge Leonard Sand, the parent company agreed to supply the subpoenaed documents. The company has paid $3.8 million to the court so far.

Only days later, Swiss authorities, citing laws that forbid the disclosure of "business secrets" to foreign governments, seized many of the documents to prevent them from being shipped to the United States.

Earlier, federal agents seized documents of the subsidiary that were already on a plane ready to take off for Switzerland.

Reportedly, Rich tried to reach an agreement with federal prosecutors, but they turned him down.