The supreme court in Nigeria has overturned the sale of a state-owned aluminum processing plant to the world’s largest aluminum producer.

Justice Afolabiyi Fabiyi ruled Friday that the sale of Aluminum Smelter Company of Nigeria (ALSCON) to Moscow-based United Company RUSAL PLC was illegal.

He said that the preferred bidder was wrongfully disqualified. He said BFI Group offered US$410 million and that RUSAL offered US$205 million.

BFI Group sued the Nigeria Bureau for Public Enterprise over the disqualification of its bid in 2004.

A spokesman for the bureau declined to immediately comment Monday.

RUSAL says on its website that it acquired a controlling stake of ALSCON in 2007.

It says it has since modernized the facility which it describes as “one of its key assets in Africa.”