He is opposed to government plans to partially privatise state-owned assets, including Solid Energy.
Green Party MP Kevin Hague was also disappointed at the report. He said anything other than 100 per cent New Zealand ownership meant assets were being used for the benefit of overseas investors.
Solid Energy had also made a commitment to retrieve the bodies of the mine workers so he was concerned there might not be the same assurance from a joint bid.
Mine receiver John Fisk of Pricewaterhouse Coopers was not available for comment. The receiver said on September 23 that final binding bids were expected in the near future.
Twenty nine workers were killed after an explosion in the mine on November 19 last year. Mining stopped and the company was placed in receivership in December.
The mine's assets include a 58.5 million tonne resource of premium high fluidity hard coking coal of which 17.6 million tonnes is estimated to be saleable. The coal is in the Brunner Coal seam and the Paparoa coal seam below is seen as a providing "potential upside" for the mine.
The mine's assets also include licenses, permits and an access agreement with the Department of Conservation.
Solid Energy operates the underground Spring Creek Coal mine nearby in a joint venture with the coal division of Cargill, a privately owned United States conglomerate that has sales of US$119.5 billion annually. The joint venture announced in 2007 was Cargill's first coal investment in this country. It purchased 49 per cent, while Solid Energy retained 51 per cent and operates the mine.
Cargill was seeking to better serve its Asian customers and Solid Energy said it brought experience in global trading from that joint venture.