Soviet science officials consider prospects of new arms control agreements "very bleak," according to a Harvard professor who returned this week from an informal U.S.-Soviet science and national security conference in Moscow.

Paul M. Doty '50, an arms control expert and member of the Biochemistry Department, said that the Soviet scientists and officials he met with earlier this month had predicted few advances in nuclear arms reduction until the Moscow government chooses a successor for ailing Soviet President Leonid I. Brezhnev.

"Outside of the formal discussions, I met with friends and found that the Soviets are very glum," Doty said this week. "They already have an accumulation of many problems; plus, they can't do much about them until a successor to Brezhnev comes on the stage."

The 76-year-old leader has reportedly been seriously ill for several years, and Communist Party officials are apparently now debating over who should succeed him.

Doty discussed Soviet politics and more technical aspects of arms control with Soviet science officials at a three-day conference at the Russian Academy of Science Institutes in Moscow.

The American 12-member delegation, organized by the National Academy of Sciences, also included two other Harvard scholars: Richard L. Garwin of the Center for Science and International Affairs and David Hamburg, professor of Health Policy and Management at the Kennedy School of Government.

Garwin and Hamburg were out of town and could not be reached for comment.

One in a series of meetings between American and Soviet scientists designed to open new channels of communication on arms control, the Moscow meeting "had none of the public orientation that other such conferences often have," Doty explained.

Instead, he said, "It was simply an attempt to get to know each other better."

Jack Ruina, an MIT professor of Electrical Engineering, agreed with Doty's characterization of the conference and emphasized the pessimism of the Americans' hosts.

"Some of the Soviets seemed quite depressed about the current state of U.S.-Soviet relations, as are many of us," said Ruina.

The two nations are now engaged in formal arms reductions talks in Geneva, Switzerland.

Doty argued that such talks usually fall victim to political posturing by both sides, despite tremendous recent progress in the mutual understanding of the dangers of nuclear war.

"I have been involved with both the political and scientific issues," he said, "and I would say that the scientific side is holding up well, as our discussions indicated."

Doty added, "If there is a political decision in Geneva to reach agreement, then we would have some things to suggest following up on."

Doty holds the Mallinckrodt Professorship of Biochemistry and heads the Center for Science and International Affairs.