The Bush administration proposed tariffs yesterday on shrimp imports from four of the largest shrimp-producing nations in Asia and South America, which it accused of hurting domestic producers by dumping the shellfish on the U.S. market at artificially low prices.

The proposed tariffs against Brazil, Ecuador, India and Thailand range from 4 percent to 68 percent -- far less than what Southern shrimpers and processors had sought, but enough to raise retail prices.

The Commerce Department will make a final decision this fall and the U.S. International Trade Commission will decide in January whether imports have damaged the domestic industry, a finding it has already issued in a preliminary ruling.

The decision, released in Washington, came three weeks after the Commerce Department proposed similar duties on China and Vietnam.

The six countries provide about 75 percent of the shrimp consumed in the United States.

"I hope that the shrimpers who brought this case will feel vindicated," said James J. Jochum, assistant commerce secretary for import administration. But he said it was unclear whether the duties would have an "immediate benefit to the shrimpers."

Southern shrimpers, who petitioned for the tariffs, said the action was a mixed victory.

"We commend the Department of Commerce for imposing anti-dumping duties, but feel that in certain instances the duties underestimate the seriousness of the violations," said Eddie Gordon, president of the Southern Shrimp Alliance, which paid for the petition.

The shrimp alliance has said dumping cut the value of the U.S. shrimp harvest by more than half from 2000 to 2002, from $1.25 billion to $560 million.

Opponents of tariffs say duties could drive shrimp prices up and do little to boost a domestic industry unable to meet demand. All four countries named yesterday denied the dumping charges.

"The only thing I can say is that the gap between the allegations and the reality is significant," said Warren E. Connelly, a trade lawyer for Ecuador.

The tariffs proposed yesterday varied according to each country's sales and production costs. Brazilian exporters faced the stiffest duties. The Southern shrimpers had sought duties as high as 349 percent for Brazil and 57 percent to 166 percent for the three other countries.

Starting next week, importers will begin paying cash deposits and bonds to cover the duties.

Southern shrimpers and processors filed the anti-dumping petition in December, alleging that their industry was on the brink of destruction because of cheap imported shrimp.

Tariff opponents argue that booming U.S. demand for shrimp and a burgeoning shrimp farming industry, not dumping, are the reason for increased imports.

The Southern Shrimp Alliance says the problem began in 2001 when Europe and Japan began blocking imports of farm-raised shrimp because of concerns of unhealthful levels of antibiotics. Also, shrimpers charge that shrimp farming has exploded only because of subsidies by the World Bank and national governments.

Workers process shrimp at a Vietnamese plant. Tariffs are proposed for imports from Vietnam, China, Brazil, Ecuador, India and Thailand.