SAO PAULO (Reuters) -A unit of Brazilian competition authority CADE has ordered soybean traders in Brazil to end a program called "Soy Moratorium" or face hefty fines, according to a decision signed by CADE's General Superintendent Alexandre Barreto de Souza on Monday and seen by Reuters.

De Souza also recommended a full-blown investigation into the signatories of the program, which is a voluntary initiative under which exporters agree not buy soy from farmers who cleared land in the Amazon rainforest after July of 2008.

Companies and trade groups Anec and Abiove, which represent global grain handlers like ADM , Cargill , Bunge , Louis Dreyfus and Cofco, have 10 days to comply, according to the document.

Anec did not have an immediate comment.

Abiove said it was "surprised" with De Souza's decision to recommend a full-blown probe. Abiove added it would take measures to defend the legality of the moratorium in addition to collaborating fully and transparently with the authorities.