BAL HARBOUR, FLA., FEB. 18 -- House Majority Leader Richard Gephardt (D-Mo.), who failed in his efforts to toughen U.S. trade law against foreign competition two years ago, said today he intends to try again.

In Florida to meet with leaders of the AFL-CIO, Gephardt said the changes in the trade laws approved by Congress two years ago have not achieved their goals. The law was designed to open foreign markets to U.S. goods and curb the flow of products subsidized by foreign governments into U.S. markets.

Although Gephardt insisted he has yet to work out details of the trade amendment, AFL-CIO President Lane Kirkland said he was under the impression that the new Gephardt initiative would be exactly like the old one -- forcing President Bush to impose quotas on any country that violated trade agreements with the United States.

Congress rejected the so-called Gephardt amendment in 1988, but it did adopt tough new trade standards that allow the president to impose tough sanctions against trade transgressors. Gephardt said today he did not think the sanctions' authority was strong enough and wanted the president to have the authority to impose restrictions for all trade with all countries.

Gephardt's call for new trade legislation came as a number of major unions, including the United Auto Workers and the Communications Workers of America, were preparing a large reception at the labor gathering here in what appears to be an effort to boost Gephardt's candidacy for another run at a Democratic presidential nomination in the 1992 elections.