Leaders of 34 American nations prepared to open a landmark summit in Chile's capital Saturday to forge ahead with ambitious plans for the world's largest free-trade area in just eight years.

Chilean President Eduardo Frei will inaugurate the Summit of the Americas, launching talks for a free-trade zone from Alaska to Patagonia by the year 2005, combining almost a billion consumers and economies that add up to $10 trillion.Presidents and prime ministers landed in Chile Friday following President Clinton, who flew in Thursday for a two-day state visit prior to the weekend summit.

"We are showing that integration is possible and that we can fulfill a centuries-old dream," Frei told reporters.

But as leaders arrived, rebels lobbed a grenade and fired machine guns at a U.S. car showroom about one mile from the summit site. No one was injured in the early morning attack by the unidentified rebels, who also set fire to a U.S. flag.

The United States, which first floated the idea of a pan-American free trade zone in 1990 and promoted it strongly at the first Summit of the Americas in Miami in 1994, has come without the special "fast track" negotiating powers that Clinton needs to ensure speedy passage of trade accords.

But Clinton used his pre-summit visit to reiterate his commitment to plans for a Free Trade Area of the Americas (FTAA) and to the other issues on the table: a regional drive to improve education, the judiciary and human rights and reduce poverty and drug trafficking in Latin America.

With Congress limiting his negotiating powers, Clinton's credibility on free trade has been undermined.

Chilean Finance Minister Eduardo Aninat said Latin America would not wait for Clinton to get "fast track" but would push on with trade accords at a rapid pace.