Brazilian power company MPX's Colombian coal mining assets will not become part of a new joint venture between MPX and German power group E.ON, but will be spun off before the JV is formed, an MPX spokeswoman said Thursday.

The Colombian coal mining assets will be formed into an independent subsidiary of MPX parent EBX Group, she said.

CCX, as the MPX Colombia subsidiary before it, will be used to supply Colombian coal to MPX's thermoelectric power projects in Brazil and Chile, with views of supplying the wider international market, the spokeswoman said.

MPX Wednesday said it will transfer up to Reais 814 million ($454 million) into the new subsidiary firm, which will be listed on Sao Paolo's BM&FBovespa Novo Mercado stock exchange.

MPX shareholders will be entitled to a share of CCX per each MPX share that they own, MPX said in a statement.

MPX started doing geological surveys in the Colombian departments of La Guajira and Cesar in 2008 and started exploring four mines in 2010 in La Guajira mining concessions, it said.

The Brazilian company said that the Colombian potential coal resources could produce up to 35 million mt of coal per year, it said.

The joint venture between MPX and E.ON aims to develop a total capacity of 20,000 MW in Brazil and Chile and will become the largest private energy company in Brazil, the companies said.

E.ON will start the operation by buying a 10% stake in MPX for around Reais 850 million ($473 million), they said.

The planned joint venture between MPX and E.ON will be responsible for all thermal and renewable energy projects in Brazil and Chile, as well as related supply and trading activities, they said.

The companies expect to close the transaction in the second quarter 2012, which includes the creation of CCX, they said.