Aditya said Hindalco had written to the company on Friday outlining its intention to reject the offer.
"The directors of ABML believe the unsolicited and highly conditional offer from Metals X materially undervalues ABML and is not in the best interests of ABML shareholders," the company said in a statement to the stock exchange.
Aditya said that, as of October 22, it held cash and equivalents of about $25 million. When combined with security deposits and an escrow deposit for the sale of its Mt Gordon mine, Aditya said it had total cash, equivalents and deposits of about $75.8 million. Not unexpected
Patersons Securities analyst Matthew Trivett said because much of the implied value of the offer was cash, the Aditya board's rejection was not unexpected.
"They [Metals X] did not put any value on the assets which have underperformed but are in the process of being turned around," he said.
Earlier this month, Aditya appointed Moelis as financial adviser to assist with a strategic review, including the potential sale of the company, and said on Monday interested parties will be approached shortly to take part in the process.
"Metals X is welcome to participate in this strategic review process, alongside other interested parties," it said.
Mr Trivett said it remained unclear whether Metals X would engage in the process.
"Metals X has no shortage of things going on at the moment, so they might not be engaged to the extent Aditya wants them to be," he said.
When the offer was lobbed, Metals X boss Peter Cook said the miner was reluctant to be drawn into a lengthy battle.
"That would have an adverse impact on the company doing other things, so we are not going to sit around," he said.
Metals X couldn't be reached for comment on Monday. Last week, vocal minority shareholder John Spalvins criticised the Aditya board for not keeping investors better informed about approaches from Metals X, and called on the board to negotiate a higher price.
Mr Spalvins told Fairfax Media he wasn't surprised the offer was considered inadequate.
"I am delighted the strategic review has a deadline of the March 2016 quarter and Hindalco support it as it puts Aditya in play," Mr Spalvins said. "The important thing is something happens because the status quo does not provide any value for minority shareholders."
