WASHINGTON - The US Congress approved free-trade agreements with South Korea, Colombia and Panama, bringing an end to years of stalemate and offering what supporters said was the biggest opportunity for exporters in decades.

The bills go to President Barack Obama, who spent two years seeking to broaden support for pacts revised from initial agreements reached by his predecessor. The South Korea deal, the biggest for the United States since the North American Free Trade Agreement in 1994, removes duties on almost two-thirds of American farm exports, and phases out tariffs on more than 95 percent of industrial and consumer exports within five years.

Wednesday's step may diminish concern that the US will turn to protectionism amid an unemployment rate that exceeds 9 percent, coming a day after a Senate vote targeting China's yuan. The approval may also give impetus to Obama's trans-Pacific trade initiative, which Japan, the world's third-largest economy, is considering joining.