Northwest Natural Gas Co., Portland, Ore., Friday confirmed the company has had discussions with Enron Corp. regarding a potential acquisition by NW Natural of Enron’s wholly-owned subsidiary, Portland General Electric Co.

In a brief statement, Northwest Natural said there could be no assurances that any transaction will result from the discussions. If a deal is completed, it would come some 6 months after a proposed $2.1 billion sale of the utility to Sierra Pacific Resources collapsed.

That sale fell through after a regulatory change in Nevada that made it all but impossible for Sierra Pacific to complete the transaction. With market capitalization of $650 million, Northwest Natural supplies gas to some 500,000 residential and business customers in Oregon and Vancouver, Wash.

Enron purchased Portland General, an electric utility serving more than 1.4 million customers in Oregon, in 1996. But the utility proved less valuable than anticipated when Enron was prevented from selling off utility contracts that allowed it to buy power cheaply.

California’s power problems also made the utility less attractive to Enron. NW Natural said it doesn’t intend to make any additional comments unless and until a formal agreement has been reached.