Brazil and Canada called for the World Trade Organization (WTO) to investigate US farm subsidies, which they said break WTO rules.

The United States rejected both calls, arguing that it was more important for the three big farm exporters to cooperate on securing a new deal in the long-running Doha trade talks, WTO officials said.

Washington is under pressure in the Doha talks to cut its trade-distorting subsidies -- the same issue under discussion -- while seeking greater access for its farm and industrial exports through tariff cuts by rich and poor nations.

Under WTO rules, Brazil and Canada can now repeat their request for dispute panels at the next meeting of the WTO's dispute settlement body on Dec. 17 and they will be established.

Countries that are the subject of a WTO dispute can object once to the establishment of a dispute panel, but cannot veto it the second time.

If all three countries agree, the two disputes could be consolidated and handled by a single panel.

Canada and Brazil said that US farm subsidies had exceeded permitted levels in every year from 1999 to 2005, excluding 2003.

"Canada estimates that during these years the United States exceeded its WTO commitment levels by billions of dollars each year," Canada said in a statement to the WTO.

On Nov. 15 Canada withdrew an earlier request for an investigation into US farm support that challenged export-credit guarantees as well as subsidies.

The United States argued that many of the measures challenged by Brazil and Canada were no longer in force and there was nothing to be gained by an investigation.

The WTO discussed the issue after a crisis was averted in its dispute settlement mechanism earlier on Tuesday, when Taiwan withdrew objections to the appointment of a Chinese lawyer as a WTO appeal judge. (Reuters)