Energy Resources of Australia has raised $380 million from institutional investors in a new share sale to extend its Ranger uranium mine.

ERA, in which Rio Tinto commands a majority stake, said it sold 249 million shares at $1.53 each to institutions in the 12 for seven accelerated renounceable entitlement offer.

ERA said in a statement on Monday that Rio Tinto had bought its full entitlement of 68.4 per cent.

The proceeds will be used to fund construction of a brineconcentrator and other water management initiatives, construction of the Ranger 3 Deeps exploration decline and associated drilling, completion of evaluation studies into the development of the Ranger 3 Deeps mine and an expanded exploration program.

ERA announced the new share sale on October 12.