Mitsubishi Corp. has agreed to pay $600 million for a 30% stake in a proposed US copper project being developed by HudBay Minerals Inc.

Mitsubishi will contribute an initial $420m (Y61.54bn) for the equity interest at closing, followed by a matching contribution of $180m within 18 months.

Hudbay Minerals (NYSE:HBM) +13.2% pre-market Wednesday after posting better than expected Q2 adjusted earnings and announcing an agreement from Mitsubishi (OTCPK:MSBHF) to acquire a 30% interest in the Copper World project in Arizona for a $600M initial cash contribution,