SAO PAULO, Feb 21 (Reuters) - Brazilian grain traders

association Abiove is challenging a new state law imposing a

1.8% levy on grain exports from Maranhao that will take effect

next week, Abiove head Andre Nassar told Reuters in an

interview.

Abiove, which represents global grains merchants including

ADM, Bunge, Cargill, and Louis Dreyfus, filed a

suit against the levy on Thursday, he said.