SAO PAULO, Sept 24 (Reuters) - Brazilian antitrust

agency CADE's tribunal will begin to review an appeal made by

oilseeds lobby Abiove and grain traders, including Cargill and

Bunge, against a measure ordering the companies to

suspend enforcement of the soy moratorium program.

According to a notice published in the official gazette on

Wednesday, the six commissioners on CADE's tribunal will start

voting on the appeal on September 30.

The fate of the moratorium, a 20-year-old corporate pact

credited with slowing soy-driven deforestation in the Amazon

rainforest, is hanging in the balance as government agencies

clash over its legality, heightening risks for global grain

traders in the world's top soybean producer and exporter.

The voluntary program, which bars some 30 firms from

buying soybeans from farmers who cleared land in the Amazon

after July 2008, also represents a potential breach of Brazilian

competition law.

Last month, CADE General Superintendent Alexandre Barreto de

Souza gave grain traders an order to suspend the moratorium or

face hefty fines.

De Souza also initiated a full investigation after

concluding a preliminary probe into the signatories of the

program, citing evidence of the companies sharing commercially

sensitive information.

The suspension was welcomed by farm groups, including

Aprosoja Mato Grosso, who say the corporate agreement is unfair

and keeps some farmers out of the market.

The general superintendent's decision, however, was

criticized by grain trader lobbies, environmental groups like

Greenpeace and Brazil's environment ministry.

One week after the moratorium's suspension by CADE, Abiove

asked a federal court to block De Souza's decision and obtained

a favorable ruling. An injunction was granted against the

suspension until CADE's tribunal makes a final ruling on the

appeal.