The United States and the Soviet Union attempted Wednesday to iron out their differences on a conventional arms-reduction treaty so it could be signed at a 35-nation summit in mid-November.

Failure could cause postponement of the Paris meeting and interrupt the easing of East-West tensions in Europe.The pivotal talks were held by Secretary of State James A. Baker III and Soviet Foreign Minister Eduard A. Shevardnadze in a hotel near the United Nations.

The two had voted Tuesday at the United Nations to impose an embargo on air traffic to and from Iraq and occupied Kuwait. The aim is to force Iraq to withdraw from the oil-rich emirate in the Persian Gulf that it invaded Aug. 2.

Baker began Wednesday's meeting with Shevardnadze thanking him for a strong speech condemning Iraqi President Saddam Hussein and for the way he chaired the Security Council session.

Shevardnadze said he was operating under a directive from Soviet President Mikhail S. Gorbachev to break the deadlock in the arms control negotiations. The two sides must "find a solution," he said.