The Carter administration announced yesterday that it is moving toward new military sales to Egypt and Sudan but denied that its plans contradict the presidential policy of restraining the arms race in the Middle East and Africa.

The announcements by the State Department follow disclosure earlier in the week that the United States has approved "in principle" a military supply relationship with Somalia. An element of superpowr rivalry is involved in all three countries, each of which has relied on Soviet arms in the past. Egypt and Sudan have broken with Moscow, and Somalia is believed to be on the verge of doing so.

The administration's plans were made known as Secretary of State Cyrus R. Vance pepares to depart Sunday on a trip to see Arab and Israeli leaders about Middle East peace prospects. Egyptian President Anwar Sadat, the first leader who will confer with Vance, has strongly urged the United States to sell more weapons to his country and to Sudan, which is on his southern border and also requested a larger U.S. role in countering in Soviets in Somalia and elsewhere in Africa.

State Department officials pointed out that President Carter's May 19 arms transfer policy allowed for the continued sale of military equipment "to promote our security and the security of our close friends." Spokesman Hodding Carter III said the new announcements reflect "a limited decision" in each case, taken in response to "new situations and new requests." Specifically, spokesman Carter said:

Consultations with Congress have begun about the possible sale to Egypt of additional C-130 military transport planes and other "nonlethal" equipment. Congressional sources identified the items as 14 C-130 transports, 12 pilotless drone reconnaissance aircraft, six aerial reconnaissance cameras and training for Egyptian military officers in the United States.

The Ford administration sold six C-130 transports to Egypt last year after Sadat cancelled his military treaty with the Soviet Union but a strong reaction from pro-Israeli lawmakers on Capitol Hill blocked any sale of additional equipment.

Sudan has been informed that the United States "is prepared to contribute to its legitimate defense needs," and an eight-member U.S. survey team will be dispatched early in August to study the country's military requirements. President Jaafar Nimeri asked for U.S. arms earlier this year after expelling Soviet military advisers. The Carter administration's initial response was the April decision to sell six C-130 transports.

Nimeri is asking for F-5E jet fighters, antiaircraft and communications equipment and trucks. The F-5Es, the most controversial item, are reported to be approved in principle by high U.S. officials but may encounter major opposition in Congress.

Somalia has been informed that the United States is prepared in principle to supply arms "in cooperation with other nations" in order to "fill any gaps" in Somalia's defense structure. This announcement was made at the State Department on Tuesday, and a similar statement was issued yesterday in London by the British Foreign Office.

Somalia is supporting a guerrilla war against neighboring Ethiopia, where the Soviet Union recently replaced the United States as principal arms supplier. In an official news agency commentary, Ethiopia yesterday charged that the U.S. offer of arms to Somalia is part of an attempt to transform the Red Sea into a "private hunting ground that modern U.S. weapons have already been captured in a clash with Somali forces, though the United States maintains that no arms have yet been sent.

The weapons for Egypt, Sudan and Somalia probably will be financed in large part by Saudi Arabia, according the U.S. officials. Sadat recently said the Saudis had promised to finance "development" of his armed forces. The Saudis are reported ready to supply $250 million to Sudan for arms. Saudi officials have been meeting with Somali leaders about arms support.

Sen. Dick Clark (D-Iowa), chairman of the Africa Subcommittee of the Senate Foreign Relations Committee, said he will take "a close look" at the planned arms sales. While he can understand the hope of the Carter administration to outmanever the Soviet Union, Clark said, "I hate to see the U.S. become more deeply involved in an arms race in Africa."

Other Congressional sources forecast major trouble for arms sales to Sudan and Somalia and less serious "questioning" about the proposed sale to Egypt. A Carter administration plan to sell sophisticated F-15 jet warplanes to Saudi Arabia, recently broached to lawmakers on an infomal basis, is in serious trouble, the sources said.