UPDATE 1-Brazil court says could annul Vale acquisition of Ferrous Resources

(Adds comment from Vale, background)

SAO PAULO, Nov 6 (Reuters) - A federal court in Brazil said it could annul Vale SA’s acquisition of midsize iron ore miner Ferrous Resources until certain environmental compliance documents have been provided, giving the company 30 days to do so, according to a decision seen by Reuters on Wednesday.

A Vale spokeswoman said the iron ore miner had not been informed of the decision and that it would adopt “appropriate measures” at the proper time.

Vale said in August that it had to temporarily halt operations at the Viga concentration plant of its newly acquired Ferrous Resources do Brasil unit due to “inconsistency in the documents.”

It said at the time the halt did not affect the Viga mine and that the documents issue did not suggest any problems with the mine’s tailings dam - a sensitive topic for Vale since the collapse of one of its mining dams killed at least 250 people in January.

Brazil’s largest iron or exporter announced in August the closing of the deal to buy Ferrous Resources from Icahn Enterprises for about $550 million including debt, initially disclosed in December. (Reporting by Alberto Alerigi and Christian Plumb; Editing by Sandra Maler)