A sweeping increase of "constructive contact" between East and West at all levels -- political, military, economic, cultural and human relations -- was proposed yesterday by 35 former government heads, Cabinet ministers, diplomats and business leaders from the United States, Western Europe and Japan.

The group called for ambitiously reshaping basic concepts for dealing with the Soviet Union at a time when "hostility runs high, contacts are sparse, rhetoric has clouded reality, . . . risks of dangerous misunderstandings" exist, and "fear of military confrontation leading to nuclear war looms large in the public mind."

What the West needs, they said, is "a coherent, widely supported policy, rooted in reality and pressed with conviction and determination," to protect its vital interests, enhance its political cohesion and offer "hope of influencing Soviet policy in a favorable direction" without expecting "the grand antagonism between East and West to end."

U.S. elder statesman John J. McCloy called the proposal -- "A Framework for Sustained Engagement" -- "a philosophy of interdependence" that will "challenge the Soviet Union to positive action."

The program, the product of a two-year review by the Aspen Institute for Humanistic Studies, was made public yesterday at news conferences here and in New York, London, Bonn, Rome and Tokyo.

Signers of the statement include former West German chancellor Helmut Schmidt, former British prime ministers James Callaghan and Edward Heath, former Canadian prime minister Pierre Elliott Trudeau, former secretary of state Cyrus R. Vance, former secretary of defense Robert S. McNamara and former foreign ministers Saburo Okita of Japan and Sergio Belinguer of Italy.

"Soviet conduct," including "trampling human rights at home, disregarding sovereign rights abroad -- of which Afghanistan and Poland are but the latest examples -- requires the West to remain watchful and strong," they said. But "apocalyptic rhetoric notwithstanding, East and West are not locked in a duel to the death."

Their proposals included:

*Multiplying "summit and subsummit meetings, bilateral and multilateral," not deferring them on the basis that "important agreements are not likely to emerge."

*Making tensions in such areas as the Middle East, the Horn of Africa and Iran and Iraq the subject of East-West discussions.

*Moving Atlantic Alliance policy toward "no early use" of nuclear weapons. McNamara noted in the news conference here that this stops short of the "no-first-use" policy, which he and others prefer.

*Creating "a strategic panel" of high-level U.S. and Soviet representatives to engage in a confidential and informal "strategic dialogue" on arms control and defense policy, plus "a network of Crisis Control Centers" in nuclear weapons states.