The United States and France signed tax treaties yesterday preventing each country from taxing people who already have been taxed by the other country.

The treaty also allows a country where a person maintains permanent residence to tax estates and gifts.

The treaties, which must be approved by the Senate, were signed by George S. Vest, assistant secretary of state, and Francois de Laboulaye, the French ambassador.

One of the documents signed is a protocol to an income tax treaty of 1967, intended to prevent double taxation of U.S. citizens in France.

A change in French law next year will subject U.S. citizens living in France to French tax on their worldwide income on the same basis as other French residents. U.S. officials feared that some Americans in France would be taxed twice for part of their income.

Under the protocol, the two countries will share the responsibility for avoiding double taxation. France will exempt Americans from their U.S. source business and employment income, and the United States will credit French tax on their U.S. source investment income in excess of the French credit.

The protocol clarifies the French tax treatment of partnership income, pension contributions and benefits and other matters of concern to U.S. citizens in France will exempt Americans from their U.S. year beginning Jan. 1.