Rio Tinto's (ASX:RIO) acquisition of the remaining shares in Energy Resources of Australia (ASX:ERA) has been approved by the Federal Court of Australia, a Friday judgment disclosure by the court showed.

"Having considered the evidence before me and Zentree's objections (and, to the extent they differ, those of the other objecting shareholders). I am satisfied that the terms set out in the Notice give a fair value for the shares in ERA," the judgment said.

Energy Resources of Australia said it will need time to review the judgment and prepare its market response, and the trading halt on its shares will remain in place until the earlier of it releasing a disclosure about the proceedings or the start of trading on June 9, according to a Friday Australian bourse filing.

The company's shares fell 2% in recent Friday trade.