U.N. Ambassador Andrew Young said today that Liberian President William Tolbert, chairman of the 49-member Organization of African Unity, was "enthusiastic" about spearheading a drive for dialogue between black Africa and Israel.

In a half-hour interview, the more subdued Tolbert, 66, said after Young's remarks that he was interested in talking with African heads of state about Young's suggestion.

Most black African states broke diplomatic ties with Israel following the 1973 Arab-Israeli war. Since the Egyptian-Israeli peace treaty, however, and the gradual withdrawal of Israel from the Sinai, the issue may have been defused.

One potential stumbling block in any dialogue between black Africans and Israel is the issue of the Palestinians, a subject that Tolbert himself raised at the opening session of the OAU summit meeting here in July. Tolbert said then that there could be no peaceful resolution of the Middle East situation without taking into consideration the plight of the "homeless Palestinians."

Young has already raised the issue of African-Israeli dialogue with President Aristides Pereira of Cape Verde Islands at the outset of his current tour of Africa. Young is heading the seven-nation tour of a U.S. trade delegation, one of his last official acts before leaving the government over the furor precipitated by his unauthorized meeting with a representative of the Palestinian Liberation Organization.

In a press briefing following an hour and a half of private talks with Tolbert, Young also said the Liberian leader said that Angolan President Agostinho Neto "wanted very much to have improved relations with the United States."

Young said that American policy on Angola has been "sort of tied in with a settlement in Namibia" with South Africa. Young indicated that Angola should be looked at separately by U.S. policymakers.

Liberia, seeking increased revenue to finance its stepped-up development efforts, is also sending a trade mission to the United States. Tolbert, known in Africa as an effective conciliator, is expected to address the U.N. General Assembly at the end of this month and to visit President Carter.

Young said that Tolbert's reaction to his suggestion about Israel was "more enthusiastic" than the response he received from the Cape Verde president.

Tolbert said he would discuss Young's suggestion "about renewing a dialogue with Israel" with other African heads of state, Young said.

In response to reporters' questions, Tolbert, who seemed surprised that Young had revealed so much of their talk, said "I'm always one to go toward talking so we can ease the way."

Tolbert is expected to broach the Israel topic with Zambian President Kenneth Kaunda during the latter's stopover here Sunday when returning from the nonaligned summit in Havana. "We will be sharing each other's views on any number of matters," said Tolbert.

Asked if Israel's ties with South Africa could act as a stumbling block to talks, Tolbert responded that it was "difficult to say if I would anticipate anything negative or positive" from other African leaders.

Young said he did not think so. "From our information," said Young, Israel "has been observing the 1977 U.N. arms embargo against South Africa. "Trade between the two countries is "insignificant," Young said.

"I do not think Israel has a need to trade with South Africa," Young said.

Young also said he felt that Arab states "would all welcome an African role in the Middle East."

His talks with Tolbert, Young continued, were not about diplomatic recognition of Israel, although he allowed that such talks could eventually lead to reestablishment of relations, "My emphasis with Tolbert has been on breaking [Israel's] isolation."

"No one likes to be isolated," Tolbert agreed. Talks between the Israelis and the Palestinians, Tolbert added, would go a long way toward "easing tensions."

Asked about his talks with President Neto of Angola about improved relations with the United States, Tolbert agreed, Talks between the Israelis talks with African leaders. He also declined to comment on his feelings on Young's resignation.

"But I do want to say Ambassador Young is highly considered by African leaders," Tolbert said.

At a dinner last night in Young's honor, the outgoing U.N. ambassador was awarded the country's order of the Star of Araic, one of Liberia's highest civic honors. The award is given for "distinguished achievements in service of fellow men."

Several hours before yesterday's award ceremony, Tolbert told Young, "We consider you a son of Africa. We salute you for all you stand for, for all that you've done."