JERUSALEM, AUG. 23 -- Israel, which has watched with concern as the United States plans major new arms deliveries to its Arab allies in the Persian Gulf crisis, is quietly preparing its own new requests for additional U.S. military and economic aid, officials here say.

Although discomfited both by the quantity and superb quality of the fighter planes and other equipment the U.S. plans to sell to Saudi Arabia, Egypt and the United Arab Emirates, the government of Prime Minister Yitzhak Shamir has decided not to voice major complaints or mobilize its supporters in Congress, officials here say.

"At a time like this, it would be difficult for us to come out in public and raise objections," said a senior Defense Ministry official today. Another government source added: "To some extent, we have to acknowledge that maybe we were wrong in the past. Maybe Saudi Arabia and the other moderate Arabs do need more weapons to defend themselves."

Israel's ability to oppose new U.S. arms sales to Arab states is somewhat compromised because it has remained largely on the sidelines in the gulf crisis, analysts here say. For some Israeli officials, the sales are another in a series of worrisome signs of a nascent U.S. strategic alliance with moderate Arabs in the Middle East that excludes Israel.

Nevertheless, Shamir and other senior officials in his government appear to believe that Israel also will be able to win new U.S. military and economic aid and swifter deliveries of sophisticated weapons as a result of the confrontation with Iraq. Despite the fact that some U.S. congressional leaders raised the possibility of cuts in U.S. aid to Israel before the crisis began, government planners in both the Defense and Finance ministries here are preparing requests for assistance beyond the total of $3 billion Israel is receiving from Washington this year.

"When all of this is over, perhaps we will seek our own reward," said one senior government official. Finance Minister Yitzhak Modai was more forthright. According to Israel radio, he said that "Israel is a strategic asset of the first order to the United States and should therefore be assisted accordingly." The broadcast also quoted Modai as saying that Israel is currently "helping the United States more than what is seen" in the crisis.

Although officials here say the government has not yet determined what its new aid requests to Washington will include, some of the military's priorities are already clear. In recent months, military officials have said Israel would like to purchase the Patriot missile air defense system, which is believed to be effective against some of the Soviet-made missiles deployed by Iraq. While military officials previously have felt the system was too expensive for Israel, additional U.S. aid might make the purchase possible.

Israel also has been negotiating with the United States on funding for the second stage of development of Israel's Arrow missile, another high-tech air-defense system designed to shoot down missiles.

The United States, which has funded 80 percent of the cost of the weapons project, had suggested that Israel cover a greater share of the second stage, which is expected to cost $240 million. But Israeli officials may insist that Washington continue to pay for the bulk of the project, sources here suggested.

Apart from U.S. military aid to Israel, now about $1.8 billion a year, Modai said today he would seek an increase in the $1.2 billion in annual U.S. economic aid Israel receives. In a speech to a delegation of the United Jewish Appeal, Modai said Israel desperately needs help in covering the cost of absorbing up to 1 million Soviet immigrants expected to arrive in the country in the next five years. Modai said the cost of that operation could reach $25 billion.

In a later address to the United Jewish Appeal group, Shamir said the gulf crisis was reaching a peak and that "in the circumstances, our major task is to prevent war, or preempt it." Israel radio said Shamir's reference to "preemption" caused a flurry of excitement among the American visitors, but that the prime minister later denied he was suggesting that Israel might stage a preemptive strike against Iraq.