President Reagan and the political leaders of Japan, Western Europe and Canada should hold a summit meeting to "strike a major global bargain" settling trade and related economic issues, former trade ambassador Robert S. Strauss said last night.

In a speech to the Economic Club of New York, Strauss -- who was U.S. Trade Representative under President Carter -- called on Reagan to initiate the meeting to stem the forces of a growing protectionist wave in Congress.

"President Reagan has the popular support, and he should spend it here," Strauss said. A text of his speech was made available in Washington.

The thrust of Strauss' speech was that the merchandise trade deficit in the United States "if not corrected and corrected soon, could have long-term consequences for the U.S. economy." He faulted the Reagan administration and "to a lesser extent" Congress for failing to come to grips with the problem.

He said he welcomed the administration's recent commitment to work with Congress to address the question of "closed markets and predatory practices," but added that this is "no substitute for a set of economic policies aimed at solving our basic problems."

This can be done only in a global context and in the atmosphere of a summit meeting, Strauss said. He argued that each of the countries must put "enough on the table to make it politically viable for the others to go along. It isn't going to be easy, and it's only the beginning of a long process."

In a separate interview, Strauss said the agreements undertaken at a summit might take 10 years to complete.

In the bargaining, Strauss said that the United States should make a commitment to reduce its huge budget deficit that has caused an overvalued dollar; intervene in foreign exchange markets when necessary; agree to reforms in the monetary system; and follow through on recently announced plans to develop a new legislative package on trade and press for a new round of multilateral trade negotiations.

The European Community, Strauss said, must stimulate economic growth in its domestic economies, and "must agree, among other things, to deal with the agricultural mess their subsidies are creating around the world." In the interview, Strauss said that the Common Market's consistent policy of dumping sugar below world market prices "is taking $6 billion out of Third World countries' income." In turn, that loss of Third World income "impacts on the whole banking system in this country," he said.

Japan would be expected to deal "aggressively with its industrial procurement policies and other nontariff barriers"; adopt policies aimed at reducing capital outflows to raise the value of the yen; and stimulate domestic demand through increased private and public spending.

Strauss decried the recent wave of "Japan-bashing" that he said "could easily destroy a relationship we both need." But he said that Japan had to share the blame for nurturing "a semi-dependent attitude toward the United States that sacrifices a great deal in the relationship in return for American tolerance of Japanese marketing successes."

For its part, Strauss said, the United States has been living "in the memory of a world that no longer exists, and we have totally overlooked the unraveling of our economic position. Now, we find ourselves, by virtue of neglect and self-indulgence, debtors instead of creditors."