A Toronto-based company wants to buy Rosemont Copper's parent corporation.

Hudbay Minerals, who owns a portion of Augusta Resource Corporation, offered to purchase the Vancouver-based company on Sunday.

“We’ve been patient and supportive share holders in Augusta since our initial investment in 2010," said David Garofalo, CEO of Hudbay. "While we are confident that Rosemont will receive all necessary permits, based on our extensive due diligence on Rosemont independent of Augusta, we believe Augusta’s management continues to be overly optimistic about the permitting timeline.”

Garofalo also said Rosemont is a solid project for his company to take over.

Hudbay has operated mines primarily in Canada, with one copper project in Peru.

Officials from Augusta said in a press release that the company’s board of directors will meet this week to discuss the offer.