‘Good Chemistry’ Summit Ends; Arms Issue Pending : 2 Leaders May Meet Thursday

President Reagan and Soviet leader Mikhail S. Gorbachev ended the formal portion of their superpower summit today, and aides said that there was “good chemistry” between the leaders but that arms-control issues remained unsettled.

“It is an open ballgame here” as to the summit’s outcome, presidential spokesman Larry Speakes told a briefing at the end of two days of scheduled talks.

While not ruling out additional meetings, Speakes said the two leaders will review their aides’ proposals at dinner tonight and make appropriate decisions.

This evening, as the two leaders and their wives chatted at the reception before dinner, a reporter shouted: “Will you be together tomorrow?”

“I think we’ll probably be seeing each other,” Reagan replied.

“Another meeting?” came the question.

“We don’t know yet,” Reagan replied.

Adhering to the news blackout imposed from the start, Speakes refused to discuss the areas of agreement or even say when and how they will be announced to a world left in suspense. “There are broad areas of agreement and other areas on which further discussions must take place,” Speakes said.

Arms-control issues are among the decisions pending, Speakes said. He refused to elaborate.

Nearly 5 Hours in Private

All told, Reagan and Gorbachev spent four hours and 51 minutes together in private during the nine-hour superpower summit--including one 90-minute stretch this afternoon.

“If the two leaders spent more than four hours together, I would think the chemistry is pretty good,” Speakes said. “They have spent more time in one-on-one sessions than they have with their advisers.

“We remain hopeful this is the start of a process of better relations between the Soviet Union and the United States.”

Reagan teased reporters waiting tonight outside his lakeside mansion, where he was to host Gorbachev and his wife, Raisa, at a final summit dinner, saying, “The news is so good we’re going to hold it for tomorrow.”

Among the experts working on details of the summit windup was Reagan’s chief arms control adviser, Paul H. Nitze. Another participant was Rozanne L. Ridgway, assistant secretary of state for European and Canadian affairs and the Administration’s expert on human rights in the Soviet Union.

Gorbachev to Meet Press

Speakes said that among the issues under review is the manner and content of the report on the summit. He also said details of Reagan’s schedule for Thursday morning, his final day in Geneva, remained to be settled.

The Soviet leader scheduled a news conference for Thursday morning. Reagan’s schedule was not announced, but a U.S. official said Reagan and Gorbachev “probably” will make a joint appearance before the press Thursday.

“It is very likely,” said the official, who spoke on condition he not be identified. “I think we’ll have a joint appearance.” He declined to elaborate.