Thirty-five religious leaders, composing one of the broadest based interfaith coalitions since inception of the civil rights movement, have issued an appeal to Congress and President Carter to set up a U.S. food reserve program as part of an international system to feed the world's hungry.

Bread for the World, a 17,000-member citizens movement that lobbied heavily for the "right-to-food resolutions" adopted in the Senate and House last year, organized the current food effort.

Three of the 35 Catholic, Protestant, Orthodox and Jewish signers of the appeal submitted to the House and Senate testified Monday before the Senate Agriculture, Nutrition and Forestry Committee. They are Bishop James Rausch, outgoing general secretary of the U.S. Catholic Conference; William P. Thompson, a Presbyterian layman and president of the National Council of Churches, and Rabbi Marc Tenenbaum, national interreligious affairs director of the American Jewish Committee.

"The 1974 World Food Conference . . . called for the establishment of a reserve composed of nationally held food stocks, the use of which would be coordinated internationally," the appeal states. "The United States, along with all the other nations represented at that conference, committed itself to such a reserve. But we have not yet acted."

While not endorsing specific bills, the appeal recommends legislation that would embrace three goals:

Enough grain to avert famines in times of scarcity.

Prevention of prices rising so high that hungry people or nations are put out of the market, or falling so low that farmers do not get a fair return on their production.

Assurance that oversupply will not lead to depressed U.S. food prices or excessive food aid, thus depressing overseas food prices and discouraging growth of food production in developing countries.

The singers included evangelist Billy Graham and leaders of the Moravian Church, Reformed Church in America, Church of the Bretheren, American Baptist Churches, United Methodist Church, Quakers, Menonites, Lutherans, two nuns' groups, the Christian Life Commission of the Southern Baptist Convention, the World Council of Churches and the Greek Orthodox Church.

Along with the appeal, Bread for the World outlined its own proposal for a 25-million-ton food reserve, two-thirds of it to be owned by farmers and held on farms.

Bread for the World also recommended support and release prices that would allow the market system to operate with normal price fluctuations but would prevent excessive declines or increases in grain prices.

It also urged a separate emergency reserve of 10 million tons of grain to be isolated from the market.

The religious leaders' appeal brought a mixed reaction from the Senate Committee.

Sen. Dick Clark (D-Iowa) thanked them for raising the moral dimensions of food supplies. But Sen. John Melcher (D-Mont.) said the Committee was more interested in economics and the mechanics of such a grain reserve than moral issues. When Bishop Rausch said "the most basic human right is the right to eat," Melcher replied that the Congress "wasn't elected on that issue."

Congress is holding extensive hearings on overall U.S. food policy because the Agriculture and Consumer protection Act of 1973 expires this year.

In other testimony during the hearings, the Interreligious Task Force on U.S. Food Policy composed of the staffs of 22 religious groups, urged Congress to "enact a price-support system that will assure a high level of U.S. food production, equity for the American family farmer and the dispersed control of food production in the hands of many family farmers."