WASHINGTON — The U.S. Senate on May 23 rejected by a vote of 71 to 27 an amendment put forth by Senator Bernie Sanders of Vermont that would have allowed states to require labels on food or beverages made with bioengineered ingredients.

The rejection came during a debate on the farm bill.

“An overwhelming majority of Americans favor G.M.O. labeling but virtually all of the major biotech and food corporations in the country oppose it,” Mr. Sanders said. “Today’s vote is a step forward on an important issue that we are going to continue to work on. The people of Vermont and the people of America have a right to know what’s in the food that they eat.”

Co-sponsored by Senators Mark Begich of Alaska, Michael Bennet of Colorado, Richard Blumenthal of Connecticut and Jeff Merkley of Oregon, Mr. Sanders’ amendment would have made clear that states have the authority to require the labeling of foods produced through bioengineering.

Mr. Sanders said food labels in the United States already are required to list more than 3,000 ingredients ranging from high-fructose corn syrup to trans-fats. But unlike 49 countries around the world, including all the countries of the European Union, the United States does not require labels identifying bioengineered ingredients, he said.

The amendment also would have required the Food and Drug Administration and the U.S. Department of Agriculture to report to Congress within two years on the percentage of food and beverages in the United States that contain bioengineered ingredients.

Both the Vermont House (99 to 42) and Connecticut House (114 to 7) voted earlier this month to make food companies declare bioengineered ingredients on their packaging. In the case of Connecticut, the bill would only take effect after five other states with an aggregate population of 25 million enact a similar law. Two of the states must be New York, New Jersey, Massachusetts or Rhode Island.