Brazilian Rare Earths (ASX:BRE) said the Australian Taxation Office (ATO) confirmed the income tax consequences for certain eligible shareholders following the demerger of Alurion Resources (ASX:ALU), according to a Friday filing with the Australian bourse.

The ATO ruled that the transaction qualified as a "demerger," with eligible shareholders who held their company shares on capital account able to obtain demerger roll-over relief, the filing said.

Additionally, the cost base and reduced cost base of shareholders' company shares before the demerger is apportioned over 89% to their Brazilian Rare Earths shares and roughly 11% to the Alurion shares received, per the filing.

Brazilian Rare Earths' shares fell nearly 3% in morning trade Friday, while Alurion Resources' shares were down almost 2%.