Nicaragua's revolutionary government has named two respected moderates to its junta, ending a period of uncertainty that began with the resignation of two junta members a month ago.

The naming of Central Bank President Arturo Cruz and Supreme Court Justice Rafael Cordoba Rivas to the junta is expected to reassure foreign governments and Nicaraguans who feared the country had taken a sharp turn to the left.

Cruz, an economist, has two degrees from Georgetown University and worked for the Inter-American Development Bank in Washington for 11 years. Cordoba Rivas, an opponent of the Somoza family dictatorship since the early 1940s, is a member of the Democratic Conservative Party, which has recently criticized the ruling Sandinista Liberation Front.

At a news conference today, Cruz, 56, acknowledged that many businessmen and other Nicaraguans feel alienated from the revolution.He said he would personally work to restore "social peace."

The appointments were announced last night by the nine-member National Directorate of the Sandinista Front, the same group that named the original five-member junta shortly before overthrowing dictator Anastasio Somoza last July.

Wearing their olive drab uniforms, eight of the nine "commanders of the revolution," lined up on the stage of Managua's Ruben Dario Theater to welcome the two new members of the junta. The announcement was made at a rally on the birthday of national hero Augusto Cesar Sandino, who fought occupying U.S. Marines in the 1920s and 1930s.

The decision to name two new members of the junta was stalled when congressional leaders in Washington announced they would postpone a vote on $75 million in aid until resigning junta members Alfonso Robelo and Violeta Chamorro were replaced.

Because of the long history of U.S. intervention here, the announcement by House Speaker Thomas P. (Tip) O'Neill (D-Mass.) was seen as an attempt to blackmail the Nicaraguan government.

Government officials say the O'Neill statement made it more difficult to name two moderates to the junta because it would look like the Sandinistas were knuckling under to pressure from Washington. Some leftist groups suggested keeping the three-member "all Sandinista" junta of physicist Moises Hassan, writer Sergio Ramirez and Commander Daniel Ortega, a member of the National Directorate.

Sandinista Commander Jaime Wheelock stressed in his speech announcing the names of the new junta members that the decision was an act of "sovereignty and of independence." The audience responded by shouting antiimperialist and pro-Sandinista slogans.

Wheelock who is also agriculture minister, reiterated the Sandinistas' promise to allow other groups, including businessmen, to have a voice in the government.

The resignation of Robelo and Chamorro caused fears here and in neighboring countries that the Nicaraguan revolution was veering rapidly to the left. Robelo, a wealthy businessman who had been considered the business representative on the junta, has begun an energetic political campaign accusing the government of encouraging "communist indoctrination" and permitting undue Soviet influence here.

Chamorro resigned because of ill health and says she supports the government, but her family's newspaper, the only independent one in Nicaragua, has been closed by a strike since the week she and Robello resigned from the junta. A new newspaper published by the striking workers came out today.

The crisis of confidence caused by this series of events set off a round of negotiations between the government and a federation of business groups.

The talks went sour, however, and the Sandinistas apparently decided they could solve the political crisis without the businessmen by naming Cruz and Cordoba Rivas, neither of whom is a member of the federation.