(New throughout, adds comments on export taxes)
By Maximilian Heath
BUENOS AIRES, June 28 (Reuters) - Commodity trader Louis Dreyfus Co's chief executive officer told Reuters on Wednesday he was "confident" Argentina would prevail in fighting an "unjust" biodiesel dumping case in the United States.
Argentina does not sell the fuel below cost, Dreyfus's Gonzalo Ramirez Martiarena said on the sidelines of the Financial Times Commodities Americas Summit.
The U.S. International Trade Commission voted last month to continue a U.S. Commerce Department investigation into alleged dumping and unfair subsidies of biodiesel fuels from Argentina. The Argentine government denies flooding the U.S. market with biodiesel.
"For us it's very important that Argentina defends against this case as it should, until the end... frankly it's an injustice," Ramirez Martiarena said.
"Argentina does not sell biodiesel below cost. There is no dumping."
Argentina is the world's No. 3 exporter of soybeans and is a top global exporter of soy oil, which is a main ingredient in biodiesel, and soymeal.
Dreyfus, which sells Argentine biodiesel, is part of the so-called ABCD quartet of global agricultural traders along with Archer Daniels Midland, Bunge and Cargill .
Ramirez Martiarena said Argentina had done a good job defending itself from dumping allegations in Europe. In September, a European Union court annulled anti-dumping tariffs the bloc had applied to Argentine biodiesel imports. The WTO had ruled in favor of the South American country, calling the measures protectionist.
"In the U.S. I'm confident that the case will be won," Ramirez Martiarena said.
On the other hand, the executive warned the Argentine government needed to further cut export taxes on soybeans or it risked losing market share to Brazil.
Days after taking office in 2015, President Mauricio Macri cut 5 percentage points off the export tax on soybeans and cut export taxes on corn and wheat. The farm sector cheered the measure, which was aimed at attracting investment.
Macri promised to keep lowering the tax by 5 percentage points per year. But faced with a wide fiscal deficit announced in October, he has instead said he would lower the tax on soybeans by 0.5 percentage points per month starting in 2018, a pace Ramirez Martiarena called "too slow."
"If Argentina does not accelerate the process of cutting soy taxes, it runs the risk of losing competitive advantage against what Brazil is developing in logistics," he said. (Reporting by Maximilian Heath, writing by Hugh Bronstein and Caroline Stauffer; Editing by Bernard Orr and David Gregorio)