WASHINGTON (Reuters) - Sen. Hillary Rodham Clinton, the Democratic front-runner in the U.S. presidential race, said on Saturday she would oppose ratification of a free trade pact with South Korea because it would harm the U.S. auto industry, among other things.

"While I value the strong relationship the United States enjoys with South Korea, I believe that this agreement is inherently unfair," Clinton said at an event hosted by the AFL-CIO labor confederation in Detroit, home of the U.S. car industry.

"It will hurt the U.S. auto industry, increase our trade deficit, cost us good middle-class jobs and make America less competitive."

The deal with South Korea, due to be signed on June 30, would lower barriers in areas ranging from agriculture and manufacturing to financial services and telecommunications.

Lawmakers from states with auto interests have argued the pact would give South Korea unimpeded access to the U.S. auto market without going far enough to ensure Seoul dismantles barriers to its auto market.

Last year, South Korea exported 700,000 cars to the United States while U.S. carmakers sold 6,000 in South Korea, Clinton said, attributing more than 80 percent of a $13 billion U.S. trade deficit with South Korea to such lopsided figures.

The two countries released a nearly completed text of their draft pact in late May. The trade deal would be the biggest for the United States since the North American Free Trade Agreement signed in December 1992.

In posting the text on its Web site on May 25, the U.S. Trade Representative's Office said the so-called KORUS pact would "level the playing field" in U.S.-Korean auto trade.

But Clinton said in a statement the deal did not go far enough to scrap "the multitude of informal barriers that severely restrict the sale of American vehicles."

"Unless those barriers fall, American carmakers will face increased competition at home and won't get greater access to South Korea's market," she said.

The U.S. International Trade Commission is due to hold a hearing this month on the economic impact of the agreement.

The earliest the Bush administration could submit the deal to Congress is late 2007, after the ITC delivers its report.

That could set the stage for a vote sometime next year, but congressional action could be delayed until after the November 2008 presidential election.

Opinion polls show Clinton, who was first lady when her husband Bill was president, in the lead among Democrats hoping to win their party's nomination to run for the presidency.

-------------------------------------------------------------------------------------------- Reuters 2007. All rights reserved

By Jim Wolf