A key Soviet foreign affairs specialist has pointedly toned down Moscow's propaganda barrage against Egyptian President Anwar Sadat's visit to Israel.

Nikolai Inozemztsev, director of the Moscow Institute of World Economy and International Relations, told a rare press conference at the Soviet embassy here today that Moscow is now taking a wait-and-see attitude toward the Egyptian leader's trip.

"If it contributes to peace in the area, then of course we can only welcome it," Inozemztsev said. "If it will postpone the Geneva conference, delay a solution, I will be able to feel just sorry about it."

This neutral stance was in sharp contrast with the initial hostile Soviet reaction last weekend. Tass, the Soviet news agency, said for example that Sadat's trip had been "determined" by the United States and "Bourgeois" nations to "undermine the united front of Arab states. A similar line was taken by the Soviet newspaper Pravda and Moscow Radio.

Inozemztsev's more sober second look is read by experts here as reflecting some uncertainty over where Arab strength lies and whether the trip might not yet favor Soviet interests. If Sadat's talks with Prime Minister Menahem Begin of Israel produce a Geneva peace conference, the Soviet Union will have achieved one of its short-run goals of regaining a central place in Middle East Diplomacy.

Experts here also suggested that sophisticated Soviet figures like Inozemztsev understood that Moscow could arouse resentment among Arabs generally by embracing the hardest line Arab states too passionately.

As an institute director, Inozemztsev is regarded as an authentic voice of more knowledgeable circles in the Communist Party. A former deputy chief editor of Pravada, he has been running the institute since 1966 and is a candidate member of the Central Committee.

He and three other "non-governmental" Soviets were in London for the annual round-table talks with leading members of Britain's unofficial foreign policy establishment. On the British side were the incoming and outgoing directors of Chatham House, David Watt and Andrew Shonfield, and the chairman of the Warburg Banking House, Lord Roll.

Inozemztsev also told reporters that the "time will come" when the Soviet Union will restore normal diplomatic relations with Israel, but he indicated that this would not happen until it suited Soviet interests in the Middle East.

He carefully avoided any questions on human rights, turning them over to Alexander Bovin, officially described as a political observer from the newspaper Ivestia, and unofficially labeled as the team's "heavy" by British sources.

Bovin suggested that Labor Members of Parliament petitioning on behalf of Yuri Oriov, the Soviet human rights protestor, "should devote more time to British domestic affairs than Soviet." He predicted that the Belgrade conference now in progress would not break up over the human rights issue because a "sensible approach" would ultimately prevail.

At the press conference and in private meetings, Inozemztsev scoffed at CIA reports of a forthcoming Soviet oil shortage. He readily acknowledged, however, that Moscow and its Eastern bloc partners had differences over the rates at which Soviet oil exports to Eastern Europe should grow in the 1980s. He said that the Soviets faced difficulty exploiting their oil in and offshore Arctic lands. He also said that the Soviets would draw a greater share of their energy from coal, natural gas and nuclear power by 1980. He firmly dismissed any question of an absolute shortage of resources.

The Soviets have recently strengthened this view by urging their partners in the Antarctica Treaty to forego exploitation of offshore oil to spare the abundant fish in the Antaractic seas. This suggests that protein rather than oil is a far more pressing Soviet problem.