One month after President Reagan and House Speaker Jim Wright (D-Tex.) announced their Central America peace initiative, many administration officials believe that events are moving so far beyond U.S. control that Reagan soon may find both Congress and U.S. allies in Central America no longer willing to support the Nicaraguan contras.

These officials -- many of them contra supporters -- say that developments over the last month threaten to undermine the contra cause despite repeated White House assurances that Reagan will fight for renewed congressional funding for the contras unless Nicaragua's Sandinista government cuts its ties to Cuba and the Soviet Union and permits pluralistic democracy.

In a series of interviews, political appointees and career officials in the State Department and other agencies said the administration has been losing the initiative to forces whose idea of a regional peace agreement differs considerably from what Reagan had in mind when he joined Wright in their bipartisan initiative.

Their original aim was to maneuver Nicaragua into a position in which it had to agree to the terms of the Reagan-Wright plan or face the possibility of renewed contra funding after Sept. 30. Unexpectedly, however, the U.S. move prodded Nicaragua, Costa Rica, El Salvador, Honduras and Guatemala to propose their own somewhat different peace plan. The Central American plan, signed Aug. 7 in Guatemala City, won Wright's blessing, but the administration has viewed it more warily because of concern that it lacks guarantees that Nicaragua will be forced to take a more democratic course.

However, many U.S. officials involved in working out a U.S. strategy for dealing with the situation criticized the administration's top policymakers for paying insufficient attention to the negotiations while concentrating on reassuring the Republican right of Reagan's loyalty to the contras and trying not to alienate Wright.

As a result, the officials said, Reagan may be unable to keep his promises to the contras if the Central American plan leads to a peace accord by its Nov. 7 deadline.

The reason, these officials said, is that in the negotiations so far, the five Central American governments have shown more interest in pursuing their own narrow, nationalistic interests than in achieving an agreement that will effectively resolve tensions throughout the region. El Salvador, they noted, primarily is concerned with those aspects of the proposed accord that would help to check the leftist insurgency in that country; Honduras seeks assurances that it will not have to absorb about 15,000 contras now fighting across the border in Nicaragua, and Costa Rica and Guatemala have similar parochial concerns.

U.S. officials fear that the four democracies, in order to win their own ends, will demand of Nicaragua only a few cosmetic, democratizing measures that can be portrayed as complying with a peace agreement sufficiently to support a demand for ending aid to the contras.

These pro-contra officials expressed concern that Wright may argue successfully that if the Central Americans reach an agreement acceptable to all of them, it would be improper for the United States to continue aiding a contra guerrilla war.

The administration has not worked out a strategy for dealing with such a possibility, the officials said. They attributed that failure in part to the fact that Reagan and most of his senior foreign policy advisers have been out of Washington during the past month. While they have been away, the situation has been treated largely as what the State Department calls a "sixth-floor problem" -- a reference to the floor on which the various assistant secretaries of state have their offices.

Even at that level, various officials report, there are deep divisions about whether the United States should try harder to influence the deliberations of the Central Americans or whether it should put its main effort into seeking new contra aid when the current funding expires Sept. 30. There also is intense debate over who should be in charge of whatever course the administration ultimately follows.

Contra supporters said it is important for Elliott Abrams, assistant secretary of state for inter-American affairs and a strong supporter of the contras, to remain as a counter to those whom the conservatives regard as favoring an agreement at any price. But, while Secretary of State George P. Shultz has expressed his confidence in Abrams, he is regarded with deep suspicion by congressional Democrats who charge that Abrams misled them about past covert support of the contras.

Other senior officials including Deputy Secretary John C. Whitehead and Michael H. Armacost, undersecretary for political affairs, are understood to believe that Abrams must be replaced if the administration is to work effectively with Congress. They reportedly have the support of powerful White House figures such as chief of staff Howard H. Baker Jr. and national security adviser Frank C. Carlucci.

Informed sources said that Harry W. Shlaudeman, U.S. ambassador to Brazil and the career diplomat with the broadest Latin American experience, recently was approached by senior administration officials to ascertain whether he would be willing to take the assistant secretary post. The sources did not say whether the approach came from the White House or the State Department.

Shlaudeman, who was Reagan's special envoy for Central America before going to Brazil, held the assistant secretary's job under Secretary of State Henry A. Kissinger in the Ford administration, and he is believed to be reluctant to take it again.

But, the officials said, the administration's failure to resolve questions such as Abrams' future is only one symptom of the confusion and drift that has characterized U.S. policy since the peace move began.

The officials cited Nicaraguan President Daniel Ortega's recent jailing of prominent civil rights leaders and exchanging sharp words earlier this week with a U.S. congressional delegation headed by Senate Minority Leader Robert J. Dole (R-Kan.) as a sign of what one official called his "increasingly cocky conviction" that Reagan cannot make up his mind about what he wants to do in the region and is fast losing his ability to influence the peace talks or to keep the contras' guerrilla movement going.