After months of openly promoting their cause, anti-Sandinista rebel leaders here have moved back into the ambiguous shadows where they began their movement more than 2 1/2 years ago.

Their renewed discretion coincides with an end to congressionally approved U.S. funding for the main guerrilla organization, the Nicaraguan Democratic Force, and orders from Honduran military commanders to keep a lower profile here in the capital and in rebel training and logistics installations along the border with Nicaragua.

The shift also has been made possible because a majority of rebel fighters have remained inside Nicaragua for the past year, removing the necessity for large-scale camps in the rugged Honduran hills that have served as a rear area for the U.S.-backed guerrilla army, rebel officials explained.

Honduran military officers were particularly upset at the open use of a large home in a fashionable Tegucigalpa neighborhood where rebel leaders kept offices, met with visitors and compiled propaganda. When foreign correspondents wrote that the busy house lay only a stone's throw from the offices of Foreign Minister Edgardo Paz Barnica, who claimed ignorance of rebel activities, the house was vacated and rebel leaders moved to more discreet headquarters.

"They are clandestine-izing their operations again," said a Honduran observer monitoring rebel activities.

Edgar Chamorro, a top rebel leader who often spoke frankly with visitors, was ordered out of Honduras last spring and now is based in Miami. Since then, the top Nicaraguan Democratic Force leader, Adolfo Calero, has reduced the number of his visits and made them less obvious by avoiding contacts here with journalists, according to Hondurans following rebel activities.

The rebel spokesman, Frank Arana, said only one member of the Nicaraguan Democratic Force Directorate, Indalecio Rodriguez, has remained permanently in Tegucigalpa. Rodriguez, previously on call to provide information, failed to respond to a recent interview request.

The guerrilla military chief, former colonel Enrique Bermudez, can be seen only with his forces in Nicaragua, Arana said. Other sources, however, said Bermudez spends time in Tegucigalpa and at Las Vegas, a rebel base in remote Honduran mountains along the Nicaraguan border. That installation, visited by a U.S. television crew last summer, has been declared off-limits to outsiders.

The Honduran restrictions began following the ouster of Gen. Gustavo Alvarez Martinez as armed forces commander last March 31. Alvarez was the chief actor, in cooperation with the Central Intelligence Agency, in making Honduras the stage for rebel activities against Nicaragua. The younger officers who replaced him, headed by Gen. Walter Lopez, have proved less willing to see their country portrayed as a launching pad for the U.S.-backed effort to overthrow Nicaragua's Sandinista leadership.

The military commanders headed by Lopez have maintained support for rebel activities on Honduran soil, according to Honduran and diplomatic sources, but have insisted on an end to the openness displayed by Nicaraguan Democratic Force leaders until this summer.

Congressional debate over U.S. funding had lifted much of the secrecy that originally surrounded rebel operations here as they started up on a large scale in early 1982 with help from CIA and Argentine advisers. Following the Falklands war that year, as Argentine enthusiasm waned and the debate became hotter and more open in Washington, CIA advisers took direct control and on at least one occasion were filmed meeting with rebel leaders.

After Congress refused last spring to provide further funding for the rebel forces, CIA officials said the money was running out. Nicaraguan Democratic Force leaders have said that U.S. funds stopped coming last May. Alfonso Robelo, who heads a smaller rebel group, the now divided Revolutionary Democratic Alliance in Costa Rica, said his anonymous sources of funds in Venezuela, West Germany and Panama also dried up at the same time.

Diplomatic sources here said that despite the announced cutoff of U.S. funds, the Nicaraguan Democratic Force has maintained a consistent level of logistics activity in Honduras without signs of suffering a cash shortage. For example, rebel leaders recently concluded a deal for thousands of feet of khaki material for new uniforms and thousands of canteens for guerrilla recruits, one well-informed diplomat reported.

Sandinista war reports and guerrilla communiques have both reported a consistent level of combat, suggesting that lack of public U.S. funds has not curtailed guerrilla efforts.

Arana said Nicaraguan Democratic Force ranks recently have swollen to more than 14,000, up from rebel claims of 10,000 last spring. Rebel officials previously have said they use the yardstick of $1 a day per man to estimate the running costs of their forces, meaning the war has cost them more than $2 million since May by this calculation.

Rebel spokesmen and Reagan administration officials in Washington have said the Nicaraguan Democratic Force is raising money from other governments and private sources to continue its struggle. According to published reports, at least several million dollars have come from U.S. corporations or individuals and friendly governments such as Israel, Taiwan and Argentina.

Rebel officials have refused to specify their new sources, however, citing fears of drying them up.

The new level of financing would mark a sharp departure from previous policies of these nations. While public U.S. funding was available, rebel leaders were saying the other sources provided only symbolic and sporadic assistance, such as a delivery of boots from Argentina.

While Israel provided several thousand AK47 assault rifles from captured Arab stocks in late 1982, for example, they were paid for with CIA funds on cash-and-carry terms through an arms dealer presumed to be working with the Israeli government, they said.