As part of a concerted effort to break out of isolation from much of the world community and enhance its "international citizenship," Israel has proposed a massive export of its technology to Third World nations to increase their agricultural productivity and relieve poverty.

Proposed by Israeli Foreign Minister Yitzhak Shamir in a speech to the U.N. General Assembly in New York this fall and elaborated upon by Foreign Ministry officials here, the program is based on a "transitional economy" concept in which the benefits would "trickle up" from a developing country's poorest rural sector to the urban-modern sector, while seeking to alleviate such long-range problems as population growth and uncontrolled migration from villages to the cities.

Its centerpiece is the sophisticated agricultural technology developed by Israel, one of the few countries to move in one generation from the status of a developing nation to a developed one. While Israel would supply the agricultural expertise, the program would be sponsored by international financing institutions, such as the World Bank, and by regional and bilateral aid programs.

The purpose is to create "islands of modern technology in a sea of poverty," said Michael Elizur, head of the Foreign Ministry's section on international organizations.

For years, Israel has been providing technical agricultural assistance to African, Asian and Latin American nations through private and semiprivate agencies, so the program would not be breaking entirely new ground. The significance in Shamir's proposal is that it has the government's public imprimatur and comes as Israel is intensifying its efforts to renew diplomatic ties with a number of Third World, nonaligned and Soviet Bloc nations.

In recent weeks, Israel initiated meetings between Shamir and the foreign ministers of the Soviet Union and Poland, and Israeli officials have been traveling extensively in black Africa attempting to renew diplomatic relations.

Elizur acknowledged that it was all part of a campaign to "explore the frontiers of Israel's diplomatic contact," although he said he did not expect instant success in restoring diplomatic ties.

Foreign Ministry officials said they were encouraged by a speech to the General Assembly by Liberian Foreign Minister Gabriel Baccus Matthews, in which Matthews called on African nations that broke off relations with Israel to "begin a reexamination of their policy."

Before 1973, Israel had formal diplomatic ties with 30 black African nations, most of which accepted the Jewish state from its independence in 1948 as a small, developing state that had also struggled with colonialism.

However, when Israel crossed the Suez Canal during the 1973 war and briefly occupied territory in Africa, all but four black African states severed ties. Israel now has relations only with Malawi, Swaziland and Lesotho, although it maintains low-profile missions or trade representatives in 12 black African countries, ranging from Kenya in the east to Nigeria and the Ivory Coast in the west.

Several Israeli development companies have continuously maintained enterprises in about 20 African states, mostly providing agricultural assistance, but the Israeli government has always portrayed them as "private" endeavors, insisting that any initiative toward resumed diplomatic ties must come from those who broke them.

The Foreign Ministry's sponsorship of the new development scheme, coupled with Shamir's initiative in renewing a diplomatic dialogue with the Soviet Union and Poland, underlined Israel's interest in reducing its diplomatic isolation. The Soviet Union broke relations with Israel in 1953, ostensibly because of an attack on its embassy in Tel Aviv. It resumed ties shortly after, but severed relations again after the 1967 war.

Aharon Wiener, chairman of the government-owned Tahal Consulting Engineers, which is active in 40 African, Asian and Latin American countries, said today, "We have a mission in this development effort. . . . We'll have to overcome political difficulties, but if the funding agencies agree, the 1980s could become the decade of development."

When asked if the underlying motive was to reestablish diplomatic ties, Elizur said, "Yes, we hope it will help us break out of political isolation. It is not directly aimed at resuming relations immediately. I prefer to put it in terms of international good citizenship. But there is a connection, and being a good international citizen does have benefits in the long run."