Feb 15 (Reuters) - Canadian miner Nouveau Monde Graphite said on Thursday it has agreed to sign a multi-year supply agreement with a unit of General Motors and would receive $150 million in equity investment from the automaker.

Under the agreement, the Canadian firm would provide 18,000 tonnes per annum of refined graphite from the second phase of its Becancour plant to GM for an initial term of six years, once it reaches full production.

The popularity of graphite anodes has soared as companies race to secure supplies of battery materials used in electric vehicles amid a global push towards cleaner transportation and fuel.

In addition to the supply agreement, GM would invest $150 million in two tranches to advance construction of the second phase of the miner's Matawinie Mine and Becancour battery material plant.

NMG added it has signed another agreement with Panasonic Energy, which combined with the deal with GM, covers about 85% of NMG's planned production from the Becancour plant. (Reporting by Roshia Sabu in Bengaluru; Editing by Krishna Chandra Eluri)