Crucial negotiations to arrange for a ceasefire in the Rhodesia war were cut short in Dares Salamm, the Tanzanian capital, today, after nationalist guerrilla leaders took sharp exception to a key aspect of the prospected Anglo-American peace plan.

An initial meeting between Britain's proposed resident commissioner for Rhodesia, Lord Carver, and black nationalist figures commanding separate guerrilla armies, Robert Mugabe and Joshua Nkomo, lasted a little more than one hour before it broke up with vague agreement to meet again, but so fixed date or place was set.

The nationalist leaders made it clear that they would not accept the role and powers of the special British representative as they have been declined in the Anglo-American proposals.

I said that Lord Carver has powers that no person on this globe ever had," Joshua Nkomo, co-leader of the Patriotie Front, told reporters after the unexpected brief meeting.

The quick breakup of the talks with little more than a formal statement of positions by both sides did not seem to augur well for the sucess of the Anglo-American peace initiative.

They represent the first round in the complex negotiations between the British and black and white Rhodesian leaders since the lastest Western peace plan was published in September. Recent statements by the two opposing sides in the struggle had already indicated there were hardening differences in their respective approaches toward both a cease-fire and the proposed transition to black majority rule in Rhodesia.

The current talks constitute the first test of British and American diplomacy in southern Africa since the American decision to back a mandatory arms embargo against South Africa, whose support has long been regarded as essential in forcing or convincing the white Rhodesian minority government to accept black rule.

The U.S. ambassador to Zambia, Stephen Low, was present at today's talks as was Lt. Gen. Prem Chand, the recently appointed United Nations special representative for Rhodesia.

The Anglo-American plan calls upon Rhodesia's white prime minister, Ian Smith, to "surrender= power to the British, the former colonial powder in Rhodesia before the whites there unilaterally declared their independence in November 1965. Britain would then arrange for elections based on the principle of one man, one-vote so that a black majority government would take power by the end of next year.

The prospects of the latest Anglo-American proposals on Rhodesia seem to go up and down from week to week, and even day to day, like a fever chart.Deep initial skepticism was followed by an upsurge of hope as the five black 'African frontiline leaders gave their backing to the plan, the United Nations showed signs of supporting it and Smith, despite his opposition, invited both Britain and the world body to send their representatives for more discussions in Salisbury.

Presently, however, the Western initiative seems to be caught in several diplomatic cross-currents that could easily doom it for failure even during this first series of talks in Dar es Salaam and later this week in Salisbury.

On the one hand, Zambian President Kenneth Kaunda indicated in an interview that he is leaning toward the idea of a direct handover of power from Smith to the Patriotic Front rather than supporting an election as provided in the Anglo-American plan.

The other crosscurrent is the increasing opposition by both Smith and the Patriotic Front toward any negotiated settlement and their seemingly mutual preference to fight it out on the battlefield.

Last week, Smith struck a highly pessimistic note about the Anglo-American plan saying. "I cannot see this initative succeeding."

He charged that the British had "put the cart before the horse" in seeking to arrange for a cease-fire before the terms of a political settlement had been worked out - a position the Patriotic Front is also likely to accept.

Smith, in an interview with the Rhodesian media, ruled out the Anglo-American proposed that the present Rhodesian army which is commanded by whites, be largely dismantled and a new national one created to replace it based on the forces of the Patriotic Front.

He also returned to his idea of a so-called "internal solution" negotiated between himself and the more moderate black nationalist leaders living inside Rhodesia and not involved in the armed struggle, namely the Rev. Ndabaning I Sithole, Bishop Abel Muzorewa and Chief Jeremiah Chirau.

Meanwhile, Nkomo has been showing show signs of supporting President Kaunda is favoring a direct handover of power to the Patriotic Front. Most likely because this approach would give him the best chance of emerging at the first black President or Prime Minister of Zambabwe, the nationalist name for Rhodesia.

At a press conference here last Thursday, Nkomo said the British would have to accept that Rhodesia was in a state a war and that the main issue was now a transfer of "undiluted power" to the "people of Zimbawe," that is, those fighting the white government.

He also indicated he thought it was up to the nationalist rather than the British to decide if and when elections should be held.

Nkomo also strongly objected to the Anglo-American idea of the U.N. peacekeeping force being introduced during the transition period. He said there should be consultation with the nationalists on whether there was any need for such a force, then precisely what its rule should be and finally where troops for such a force should come from.

Earlier, Mugabe, who is leader of the Patriotic Front faction with the largest guerrilla force, said he would never accept a cease-fire until Smith had resigned or been removed from power.

At Port Elizabeth, South Africa, the first 12 black students of the 474 arrested after clashes with police earlier this month went on trial today and were acquitted charges of violence and attending an illegal gathering.

The violence erupted on Oct. 11 when police attempted to disperse a crowd of about 700 high school students in the black township of New Brighton.

tr for folo.