Edison International late Thursday reported a 55 percent drop in its third-quarter profit as the company struggled with low prices in its power generation business and higher costs at its Southern California Edison unit.

After the markets closed, the Rosemead company reported net income of $190 million (58 cents a share), compared with $426 million ($1.30) in the same period a year earlier. Operating revenue rose 5 percent to $4.1 billion.

Analysts surveyed by Thomson Reuters on averaged expected profit of $1 a share on revenue of $3.6 billion.

SoCal Edison, the state’s second largest electric utility, has a request pending with the California Public Utility Commission to boost rates this year to pay for increased spending on its power distribution system. Costs related to the January closure of the 2,200-megawatt San Onofre nuclear power plant cost 9 cents a share from inspection and repair costs and an additional 6 cents a share in shutdown-related costs.

With San Onofre out of service, replacement power costs were $221 million during the quarter. The PUC is considering whether customers should have to pay for costs related to the shutdown of the plant, which is located 60 miles south of Los Angeles.

Edison International is working to restructure about $3.7 billion in unsecured debt at its Edison Mission Group to lower costs. The power generation unit has been hurt by a decline in energy prices, combined with increased costs to comply with environmental requirements at its coal-fired power plants.

Shares earlier closed down 21 cents, or less than 1 percent, to $46.71 on the New York Stock Exchange.