U.S. farmers will be able to compete for an estimated $2 billion in sales to Iran, Libya and Sudan under new rules effective today, top Clinton administration officials said yesterday.

The long-awaited rules put in place a policy change announced by the Clinton administration on April 28 to exempt sales of food, medicine and medical equipment from U.S. economic sanctions. Iran, Libya and Sudan are forecast to import an estimated 12 million tons of grain in 1999 and 2000, Agriculture Undersecretary Gus Schumacher said.

Treasury Deputy Secretary Stuart Eizenstat told reporters the new regulations establish an expedited licensing procedure for bulk commodity sales to the three countries, which remain under general U.S. sanctions because of their suspected support of international terrorism.

For sales of other food, medicine and medical equipment, a two-step licensing procedure has been established, he said. Food is limited to those agricultural products ultimately consumed by humans or animals, which excludes cotton and tobacco, Eizenstat said.

U.S. farm products "are likely to be extremely competitive" in the three countries because of a huge domestic surplus that has depressed U.S. commodity prices, Schumacher said. Administration officials estimate that the rule change could generate $500 million in U.S. farm exports.

Iranian newspapers yesterday quoted a deputy trade minister as saying Iran was unlikely to buy from the United States until all sanctions were lifted. Eizenstat said it was unclear whether that represented an official view or just the speaker's opinion.

"The key is, our products will be available" if those countries want to buy, he said.