If French voters on Sunday approve a plan for European economic unity that produces a stable and strong Europe with a single currency, companies and investors in the United States and much of Asia would have reason to exclaim, \o7 "Vive la France!"\f7

If implemented as designed, the Maastricht treaty for European economic and political integration would create the kind of stability that would help reduce the threat of European protectionism and create a more secure and attractive climate for investment in Europe, according to economists and business executives.

The planned economic and monetary unification of the 12-nation European Community would eliminate the need for the kind of currency speculation that leads to big swings in the value of the dollar and Japanese yen and make international trade more predictable, they added.

On the other hand, the U.S. and Japanese economies would not be hurt if the EC failed to further integrate its economies--the United States and Japan have had a trade surplus with Western Europe--unless the failure of unification further depressed European economies.

Maastricht calls for the establishment of a central European bank and more coordination on economic policy. Such provisions would constrain members of the EC, leaving each member nation less room to adopt their own protectionist policies.

EC members already have uniform tariffs on most manufactured goods, and that uniformity would be ensured under Maastricht. However, some EC members have protectionist policies on agricultural goods, and there are no guarantees that such protection would end under Maastricht.

The Maastricht plan would also require EC countries to more closely coordinate their positions on political and security matters, an objective designed to foster more unity on crucial policies.

If such unity were achieved, the EC would be better equipped to deal with crises such as the civil war that has fractured a once-united Yugoslavia, said Ella Krucoff, a spokeswoman for the Delegation of the EC Commission, a Washington office that serves as an embassy for the European group.

Such stability is important because investors tend to worry that turmoil in one area will spread and hurt the economies of neighboring countries, said A. Nicholas Filippello, chief economist at the St. Louis-based chemical giant Monsanto and former adviser to Murray Weidenbaum during Weidenbaum's stint as President Ronald Reagan's chairman of the Council of Economic Advisers.