President Bush won't have long to savor his hard-fought congressional victory on streamlined

trade negotiating powers. Now comes the hard part, and officials say Bush's goal of a unified North American market is years away.The president's decision to consult with Congress every step of the way - one of the concessions the administration had to make to win Democratic support - could further slow down an inherently slow process, some aides suggest.

The 1989 U.S.-Canadian free-trade agreement, often held up as a model, took three years of difficult negotiations. And it didn't undergo nearly as intensive congressional scrutiny in the early stages as has the fledgling U.S.-Mexican free-trade effort.

"It won't be quick and it won't be easy," said presidential spokesman Marlin Fitzwater.

The Senate's 59-36 vote on Friday completed congressional action to give Bush special "fast track" trade negotiating authority for another two years.

This streamlined authority allows him to submit trade agreements to Congress for a simple yes or no vote, without the possibility of amendments.

Presidents already have such authority under the Constitution on treaties.

But unlike treaties, which only require Senate ratification, trade agreements require changes in U.S. law and must go to both houses of Congress like any other piece of legislation.

In addition to opening the way for negotiation with Mexico, the action could help revive international trade talks in Geneva among members of the General Agreement on Tariffs and Trade.

Those talks broke down last year because of a deadlock between the United States and European nations over a U.S.-backed plan to eliminate all government subsidies of agricultural exports.

Bush, after weeks of having small groups of lawmakers to the White House each day to lobby them on the measure, was so elated at the final Senate vote that he couldn't wait to share the news with Mexican President Carlos Salinas de Gortari.

So he called him from his Marine One helicopter en route to here from Boston where he had given a speech to a trade group.

Bush and Salinas agreed to keep free-trade momentum going by scheduling the first negotiating session as soon as possible. Bush picked the week of June 11, Fitzwater said.

The session will be a three-way gathering with negotiators from the United States, Mexico and Canada.

The site for the opening meeting has not yet been selected, but the formal talks will likely move back and forth between Mexico City and either Washington or a Texas city, said administration officials.

Tim O'Leary, an aide to U.S. Trade Representative Carla Hills, said deputy trade representative Julius L. Katz would head the U.S. team in the talks.

He said Canadian negotiators were expected to sit at all the sessions, since a Mexican-Canadian agreement must also be signed if the three nations are to create what Bush is fond of calling "a single market of 360 million people."

O'Leary said that "we're not setting a time limit" on the talks.

But he noted that the Canadian agreement took three years to complete - including 16 months of nearly non-stop negotiations at the end.

"The trade agreement with Canada will serve as a baseline, a guide," O'Leary said.

The United States also has a free-trade agreement with Israel.

The Canadian pact, signed in January 1989, phases out all tariffs, quotas and other trade barriers over a 10-year period.

In an effort to win support in Congress, the president gave his word that the U.S. negotiators would try to develop terms that would protect U.S. jobs and the environment.

Opponents of the pact included labor unions, environmentalists and consumer groups, who have predicted job losses and degradation of the environment under a U.S.-Mexico free-trade agreement.

"We're going to be looking over the shoulders of our negotiators," cautioned House Majority Leader Richard Gephardt, D-Mo.

Gephardt initially was skeptical of the measure, but administration officials credited his eventual support with helping to push the bill over the top in Thursday's crucial House vote.

On Friday, Bush said he would uphold his end of the bargain. "I pledge to the members of the United States Congress that we are going to consult as we go along. We will not bring to them a bad trade agreement . . . No point to that."

Once a trade agreement is completed, Congress has 90 day on which to act.

And Bush is predicting passage well in advance for the Mexican pact even though not a word has yet to be written. "It will pass, and it will pass because we will be consulting with the Democrats and the Republicans in the Congress," he said in Boston on Friday.

Of course, administration officials are also keeping their fingers crossed that the negotiations can be wrapped up within the two-year "fast track" extension. Otherwise they may find themselves back before Congress in May 1993 locked in another fast-track battle.