The US energy giant had been under pressure from the markets to fix up its balance sheet following the Enron collapse and the California energy crisis.
NRG owns the largest collection of privatised power stations in Australia with a total generating capacity of more than 5000 megawatts supplying large parts of Victoria, South Australian and Queensland.
Together with American Electric Power, TXU Inc and CMS Energy, the exodus of NRG from Australia's electricity sector means about $10 billion worth of assets are now on the market.
Some possible suitors for NRG's assets include China Light & Power, Singapore Power, Duke Energy, Cheung Kong Infrastructure/Hong Kong Electric and International Power.
