The development of the underground mine at Oyu Tolgoi in Mongolia took a significant step forward with the signing of the Oyu Tolgoi Underground Mine Development and Financing Plan by the Government of Mongolia, Turquoise Hill Resources and Rio Tinto. The plan addresses the key outstanding shareholder issues and sets out an agreed basis for the funding of the project.

With a new pathway to development of the underground mine agreed, the focus now shifts to finalizing the project finances, the feasibility study and securing all necessary permits so that the underground mine development can proceed.

Rio Tinto Copper and Coal chief executive Jean-Sébastien Jacques said, “The resolution of the outstanding issues reinforces the principles of the investment agreement signed in 2009, which underpinned the $6 billion invested in Oyu Tolgoi to date, and provides a clear and stable framework for the future.”

“The agreement outlines a pathway to restarting development of the underground mine, and builds on the value that has already been unlocked for Mongolia from the operation of the open-pit mine, which is providing jobs and other economic contributions as well as best practices in mining standards,” said Jeffery Tygesen, CEO, Turquoise Hill Resources.

The construction of the first phase of the pioneering Oyu Tolgoi project – the open-pit mine – was completed on schedule in less than 24 months. The operation celebrated 1 million metric tons (mt) of copper concentrate shipped in March 2015, less than two years after first production left the mine.