Northern Electric is understood to have made a formal offer for the subsidiary with financing from Goldman Sachs, in the first round of the auction, according to people familiar with the situation.
The group, which was not taken through to the next stage in the auction, is now thought to be interested in re-entering the sale being handled by Morgan Stanley.
Buffett has been keen to increase his interest in the UK and has already looked at buying a number of other utility assets including Midlands Electric and British Energy. Northumbrian would provide geographical overlap in the North East.
However, if Northern Electric does bid, the deal will be to increase its supply base, rather than bulk up its customer base. CVC, the UK buy-out group, has been told it is the preferred bidder.
Apax Partners, is believed to have been told its bid fell short. However, it is understood that Morgan Stanley Capital Partners, the investment bank's private equity group, is still in the auction.
The auction for Northumbrian attracted a high level of interest from financial buyers who are looking for asset-backed companies with stable cash-flows that they can securitise.
Source: Financial Times