The seven industrialized democracies have an opportunity at the Houston economic summit to help the reformers in the Soviet Union who want to make their country a free-market democracy. What is needed are two initiatives for coordinated Western aid -- one economic, the other political.

The first element is an economic package that should not start with large-scale loans, which in the present disorganized state of the Soviet economy would bring no lasting benefits and could not be repaid. What the Soviet Union most urgently requires is a credible program to transform it into a market economy, coupled with the building of the necessary institutions to carry such a program out. These institutions must include laws that create and protect private property rights, a stock market, a private banking system, anti-monopoly legislation and an organized process of privatizing state enterprises.

A week of economic discussions in Moscow last month with senior Soviet officials and academics reinforced my conviction that the Soviet Union cannot devise and carry out such a program on its own. It lacks people with the necessary knowledge and experience in free-market economics, and it badly needs Western advice and technical assistance.

Nor can these needs be supplied by occasional brief visits of Soviet delegations to the International Monetary Fund and the World Bank in Washington, to the Organization for Economic Cooperation and Development in Paris or to the European Commission in Brussels. What the Houston economic summit should offer Mikhail Gorbachev is the establishment in Moscow as soon as possible of an international team of experts -- selected by these organizations -- who could work with Gorbachev's economic advisers and those of Boris Yeltsin at the Russian republic level.

The purpose should not be to impose a Western design upon the Soviet Union but rather to help it fashion a program that would provide the basis for a subsequent package of financial aid.

Since the IMF, the World bank, OECD and EC cannot finance such a joint mission for a country that is not a member, a modest technical assistance trust fund of, say, $5 million could be created in the United Nations Development Program on behalf of non-market economies in transition, for which these organizations could serve as executing agents. There is reason to believe that Gorbachev and Yeltsin would welcome such an initiative provided it were clear that it was intended as a consultative mission and not as an infringement on Soviet sovereignty.

But it is obvious that a program of economic liberalization in the Soviet Union cannot succeed without a parallel program of political liberalization. The latter process requires an alliance between Mikhail Gorbachev, Boris Yeltsin and those reformers on their left who want to transform the Soviet Union into a real free-market democracy. Such reformers include such men as Anatoly Sobchak, the mayor of Leningrad; Gavril Popov, mayor of Moscow; Sergei Stankevich, Moscow's deputy mayor; and Viktor Aksyuchits, leader of the new Christian Democratic Party.

Western governments cannot help such reformers directly without risking the charge of interference in the U.S.S.R.'s internal affairs. But they could agree at Houston to encourage a coordinated program of aid on the part of their political parties, trade unions and civic groups. In the United States, a leading role could be taken by the National Institute for International Affairs of both the Democratic and Republican parties, which already have a successful track record of assisting democracy in such countries as Chile, Nicaragua and Czechoslovakia. Together with European groups, they could offer advice on the drafting of the U.S.S.R.'s new constitution, on the effective operation of the Soviet and republic parliaments, and on the creation of an independent judiciary.

A popular election for president of the Soviet Union is now scheduled for 1994, and Gorbachev will be under pressure to advance that date to 1991 or 1992. By providing the non-Communist forces with needed hardware (computers, fax machines, and publishing equipment) as well as advice on running political campaigns, the West can help them -- and perhaps reform Communists as well -- to compete in these elections on the basis of equality.

The skeptics will say that a liberalized Soviet Union is a chimera and that the country's future holds nothing better than chaos followed by repression. It is true that in the light of Russia's tragic history, an orderly transition to free-market democracy is a long shot. But the seven leaders at Houston should make a prudent investment in that long shot, given what their countries and all humanity have at stake. The writer, a former U.S. ambassador to Italy, recently led a private delegation to Moscow for talks on U.S.-Soviet economic cooperation.