Washington: Key state senators warned the Bush administration on Friday they would not support a world trade deal that cuts US farm subsidies more than it opens foreign markets to American farm exports.

A successful deal must provide new export opportunities that are "comparable in magnitude" to any farm subsidy cuts the United States would have to make, Senate Agriculture Committee Chairman Tom Harkin, an Iowa Democrat, and 16 other panel members said in a letter.

"Anything less will not receive our support...If you are presented with an unbalanced text, we urge you to reject it in favor of continued negotiations," the bipartisan group wrote to US Trade Representative Susan Schwab.

The letter came just before a high-stakes meeting in Geneva to try to reach a breakthrough in nearly 7-year-old world trade talks.


Although negotiators weren't expected to reach a final deal next week, they are being asked to agree on formulas for cutting farm subsidies and tariffs that were originally supposed to be decided in 2003.

If they don't achieve that, many believe the Doha round trade talks will go into the deep freeze for years.

Any deal reached by the White House must be approved by Congress, forcing US negotiators to pay close attention to farm state lawmaker demands.

Earlier this week, farm groups sent a similar letter to President George W. Bush complaining that current proposals ask them to give up more in domestic farm subsidies that they can expect to gain from new export opportunities.