MEXICO CITY, NOV. 5 -- Mexico and the United States are ready to sign an important trade pact thatMexican officials hope will protect their export-based economic strategy against a possible U.S. recession.

The accord is to be signed at a ceremony here Friday by U.S. Special Trade Representative Clayton K. Yeutter and Mexican Commerce and Industry Secretary Hector Hernandez Cervantes.

While this "historic agreement" will not in itself "solve all the trade problems we have between us, it represents a positive step in the upgrading of our trade relations," Yeutter said on his arrival here today.

The so-called framework agreement -- or "understanding," as it is officially labeled -- took more than a year to negotiate. It establishes formal mechanisms for the resolution of cross-border trade disputes for the first time since the expiration of another bilateral accord in 1949. The pact stipulates that talks must begin within 30 days of the filing of a trade-related complaint by either government.

The understanding does not commit either country to immediate policy changes. But it does order the two governments to begin substantive negotiations within 90 days on agricultural commerce, textile quotas, services and other trade conflicts.

Maintaining an import-export flow across the border of some $30 billion annually, Mexico is the third-largest U.S. trading partner after Canada and Japan. It handles trade conflicts with Washington through ad hoc negotiating arrangements or through the cumbersome procedures of the General Agreement on Tariffs and Trade.

The accord's final draft was approved Oct. 12 by the Mexican Cabinet after consultations with business leaders and the Mexican Senate.