The Anglo American plan to transform white ruled Rhodesia into a nation with a black majority government has been delayed but not sabotaged by Rhodesian Prime Minister Ian Smith's overtures to moderate black leaders U.S. officials said yesterday.

"Sure it's been delayed." said Richard M. Moose Jr., assistant secretary of state for African affairs. "But we will stick with the essential elements of the plan."

And he asserted, "there is still a good chance that indepence could come in 1978."

Another high administration official, who declined to be named said, "We and the British remain committed to the plan. Smith can stall implementation, but he can't block it."

The British-U.S. plan envisions majority rule and legal independence for Rhodesia sometime next year, but some diplomats have privately expressed doubt over the timetable because of Smith's actions and differences among black African leaders over the plan.

Last week saying the Anglo-American initiative had failed. Smith announced that he had invited black moderate leaders in Rhodesia to negotiate with the white government on a constitutional settlement.

He said that since these leaders in Rhodisia to negotiate with the white government on a constitutional settlement.

He said that since these leaders had endorsed the idea of safeguarding white interest, he would accept "the principle of majority rule based on adult suffrage."

While he did not say he would accept universal adult suffrage, he indicated he would give up his insistence on a "qualified franchise" based on income and education requirements so long as there are other ways of assuring minority rights. That led to press reports that Smith had finally, if conditionally, accepted the principle of one person, one vote.

Initial British reaction to Smith's comments on adult suffrage was more positive than U.S. reaction, raisng the question of whether Britain might be moving in a different direction from the United States in dealing with Smith.

Moose emphatically denied that there is any divergence. He said his telephone discussions with British Foreign Secretary David Owen over the last few days convinced him that Owen "is still committed to the British-American plan."

Moose appeared more sanguine about prospects for the plan, which the United States is committed to push than diplomats in some other capitals. In London there is widespread belief that Owen is ready to scuttle a key clement of the plan - formation of a new army of an independant Zimbabwe, the African name for Rhodesia around the guerrilla forces fighting Smith's regime.

But Moose said Owen agrees with the United States that Patriotic Front forces should have a leading role in the new army and in elections during the transition from white to black rule.

For the United States, the Next step will come when Secretary of State Cyrus R. Vance meets with Owen next week at the NATO ministerial conference in Brussels.

They will decide then whether to seek another round of talks with the parties involved and might also devise "an elaborated version" of the Anglo-American plan Moose said.

According to U.S. officials, the following principles of the plan are not negotiable:

Transfer of power from the Smith regime to a British-run transitional government for six months.

A new constitution with provisions for universal adult suffrage, a bill of rights that cannot be easily amended and that would allow citizens redress of grievances through the courts, and an independent judiciary.

A cease-fire

Free and impartial elections during the transition period and amnesty for those (the whites) who supported Rhodesia's breakaway from the British in 1965.

Agreement on the disposition of Rhodesian and guerrilla armed forces, giving the latte a leading role in the New Zimbabwe army, and supervision of the cease-fire by a United Nations force.

What is negotiable, the U.S. sources said, is how these principles are implemented.