Andrew Young, U.S. ambassador to the United Nations, suggested today that a compromise settlement may be in prospect in the dispute over Rhodesia's government.

Young said he believes that Rhodesian Prime Minister Ian Smith "realizes more and more that the Rhodesian whites cannot win" their struggle to retain white-minority rule, and that he has discerned among black-nationalist guerrillas a "sense of urgency and a willingness to cut short the armed struggle somewhere short of marching into Salisbury," Rhodesian's capital.

Sources here, where the United Nations is sponsoring a week-long world conference for action against apartheid, said that Young and British Foreign Secretary David Owen will meet Saturday in Lusaka, Zambia, with the five black African government leaders most concerned with a negotiated Rhodesian settlement.

They will discuss the latest Anglo-American efforts to bring about a peaceful transition to black-majority rule in the former British colony by the end of 1978.

The timing of the Lusaka meeting was agreed on by Young and Zambian President Kenneth Kaunda when they conferred here last night, the sources said.

Also scheduled to attend the Lusaka meeting are the presidents of the other "from-line" black African states - Angola, Botswana, Mozambique and Tanzania.

If the latest initiative worked out in recent high-level consultations in Washington and London, receives the front-line presidents' blessing, the sources expect that Joshua Nkomo and Robert Mugabe, leaders of the Patriotic Front controlling black Rhodesian guerilla forces, will follow suit.

In that case, Young and Owen are generally expected to travel to either South Africa or Rhodesia, and possibly to both, to push the negotiations forward.

Observers speculate that the Anglo-American proposal centers on establishment of a mixed security force composed of nationalist guerillas and elements of the present Rhodesian armed forces.

Until recently the Patriotic Front leaders have rejected this suggestion, insisting their troops alone assure order during a transition from white rule to black.

The sources said it is not clear what Smith's role would be under the new plan.

While the Rhodesian question was occupying some leaders in private, apartheid in South Africa held the public stage as 500 delegates from more than a hundred countries gathered in the National Theater for the opening session of the U.N. conference.

Leslie Harriman, the Nigerian ambassador to the United Nations who heads the special committee against apartheid, told reporters, "We did not invite the Western powers to Lagos to attack them. We would like to have frank discussions with them and expect them to reciprocate."

But little of such moderation was discernible in the opening speeches of U.N. Secretary General Kurt Waldheim; Lt. Gen Olusegun Obasanjo, the Nigerian head of state; Kaunda; Shirley Ameasinghe, president of the U.N. General Assembly; former Swedish Prime Minister Olof Palene and the leaders of the two rival south Africa liberation movements.

Their addresses included the traditional demands for economic sanctions and a total arms and oil embargo against South Africa.

Many Western powers have opposed such demands as self-defeating, especially while South Africa's cooperation is needed in bringing about peaceful change in Rhodesia and Namibia (Southwest Africa).

Obasanjo specifically warned that his country is "compiling information on all those governments who pretend to be Africa's friends but allow themselves to be used as a weapons laundry for South Africa - all for limited economic advantage." He went on: "We are mounting a surveillance on all those enterprises who depend on our raw materials and markets but continue to help our enemies."

Alluding to Nigeria's economic weight - its gross national product, largely from oil is expected to surpass South Africa's this year for the first time - he said, "Such enterprises must decide now to choose between us and our enemies and all that goes with that choice."

Kaunda sounded a similar note, charging that international capitalism sustains apartheid because multinational corporations get "big profits from the system." "The West must be made to choose," he said.

Even the usually mild-mannered Waldheim said that "There can be no peace in South Africa so long as three-quarters of its people are excluded from the mainstream of its national life."

[Reuter news agency published a note to editors explainig that it cannot provide direvt coverage of the U.N. conference in Lagos "because the Nigerain government has refused to allow Reuters to reopen its reporting office in Lagos which was closed by the authorities there in February 1976."]