A number of companies are interested in buying the Whirinaki power plant.
The Government is trying to sell the diesel-fired reserve plant after Meridian decided it didn't want it as part of industry-wide asset swaps to boost competition.
The Ministry of Economic Development, which is handling the sale, won't release the number of bidders, citing commercial confidentiality, but says there is more than one potential buyer of the plant.
Both it and The Treasury are negotiating with the final bidders to find a preferred buyer, and the process is on track for a sale on either 1 December 2011 or 1 October 2012.
At the moment, the costs of running the station are funded by the Electricity Authority through a levy on power companies, but they run out in September may have to be extended.