The Carter administration has decided to increase U.S. aid to Israel by $285 million, but rejected that country's request to be allowed to sell advanced fighter-bombers to Ecuador.

The decisions, amde known yesterday, are the first tangibles signs of the new administration's policies toward military support of the Jewish state. President Carter, during his campaign, criticized the Ford administration for not giving enough aid to Israel and promised to supply assistance "in the full amount necessary." At the same time, Carter was highly critical of increased sales of sophisticated arms.

President Ford in his final budget request proposed to supply $1.5 billion in grants and loans to Israel, which is by far the largest single beneficiary of U.S. assistance. Carter's planned increase of $285 million is in respone ro Israeli pleas that the Ford total was inadequate.

Israel has requested $2.3 billion in aid for the coming fiscal year. It is unclear whether Israli officials and their allies in Congress will continue to fight for the higher total. A battle with the Ford administration over aid levels created tension in relations between the two government last year.

In order 10 maintain its relationships with the Arab world, the Carter administration has decided to increase its request for Egypt, Jordon and Syria in rough proportion to the Israeli increase, according to administration officials. This would bring proposed aid for Egypt to about $750 million, for Jordon to about $220 million, and for Syria to about $90 million in fiscal 1978.

Secretary of State Cyrus R. Vance is scheduled to visit all these countries, plus Lebanon and Saudi Arabia, in an eight-day journey beginning next Monday. Vance held separate meetings yesterday with the five ambassadors of Arab countries he will visit and with Israel Ambassador Simcha Dinitz.

The decision to reject Israel's request to sell 24 of its Kfir fighter-bombers to Ecuador was announces by State Department spokesman Frederick Z. Brown, who said such a transaction "would run counter to our policy against the sale od advanced and sophisticated aircarft to Latin America."

Israel was required to seek U.S. approval bacause the warplanes' engines are American-made.

In Juresalem, Defense Minister Shimon Peres said Israel "will never be reconciled" to U.S. refusal to permit export of the Kfir. He said U.S. desapproval would simply transfer the proposed $150 million purchase to France, which also has been negotiating with Ecaudor own warplanes. Peres spoke before the U.S. decision was announced.

Ecaudor's neighbor, Peru, recently purchased 36 Soviet SU-22 fighter bombers ager the Uniter Stated refused to sell it advanced aircraft in keeping with its long-standing pplicy in Latin America. Fears have been expressed that the Soviet action and sales by France Israel and other countries will fuel a Latin arms race.

In another development regarding Israeli weapons, spokesman Brown said yesterday that proposed U.S. sales of tanks, artillery, night-vision sights and highly sophisticates concussion bombs to that country is under active review at the State Department. The sales were approved by Ford during the presidential election campaign without a full review by U.S. agencies.

After his meeting with Vance, Dinitz said he had received no indiction that any weapons promise by the Ford administration. But he would be reversed by the Carter administration. But he would not be definite in statements about the concussion bomb sale, which is reportedly opposed by some State Department officials.