SDG&E; May Forfeit Plant Stake

San Diego Gas & Electric would forfeit its 20% interest in the San Onofre nuclear power plant if it declined to participate in a planned $680-million equipment replacement, according to a regulatory filing Wednesday.

Southern California Edison, owner of 75% of the generating station in northern San Diego County, said in its annual report that an arbitrator decided SDG&E;’s plan to opt out of the investment would result in its losing the stake. The ruling must be approved by the California Public Utilities Commission.

SDG&E;, a unit of Sempra Energy, had expected the arbitrator to cut its stake no lower than 14% and may choose to participate in the investment if it found the commission’s decision unacceptable, spokesman Peter Hidalgo said.

Southern California Edison, a unit of Rosemead-based Edison International, is planning to make the investment to install new generators at the plant.

The city of Anaheim, which owns 3.16% of the plant, would also forfeit its stake by choosing to opt out, based on the arbitrator ruling, Edison said. The city of Riverside owns 1.79% of the plant and is choosing to participate in the investment.

Shares of San Diego-based Sempra fell 42 cents to $40.42 and Edison rose 3 cents to $33.58. Both are traded on the New York Stock Exchange.