The dismal performance of North American utility stocks continued through the third quarter of 2023, dragging the market capitalization of the biggest names in the sector.

Sector indexes widely underperformed the broader S&P 500 index in the 12 months through the third quarter, with higher interest rates largely driving the recent stock sell-off. The S&P 500 Electric Utilities (Sub Ind) index fell 5.9%, the S&P 500 Multi-Utilities index slid 9.1% and the S&P 500 Utilities index dropped 7%.

The S&P 500 had a positive return of 21.6% for the 12 months ended Sept. 29, according to S&P Global Market Intelligence data.

NextEra Energy Inc. logged the largest quarter-over-quarter percentage decrease in market cap to $115.94 billion as of Sept. 29. Despite the 22.8% drop, the company remained the largest and the only utility with a market cap above $100 billion.

NextEra Energy stocks recently took a beating after NextEra Energy Partners slashed its limited partner distribution per unit growth rate. Some analysts, however, see NextEra Energy being insulated from the troubles at the yieldco, which only accounts for less than 5% of its consolidated earnings.

Meanwhile, Dominion Energy Inc. slid to seventh place from fourth a year earlier, after recording the largest year-over-year drop in market value. In September, the company decided to offload three gas utilities, earmarking all after-tax proceeds for debt reduction.

The development was seen as a major step relating to its "top-to-bottom" business review announced nearly a year ago.

Constellation Energy Corp. was a bright spot among its peers, registering both quarter-over-quarter and year-over-year gains in its market cap. In September, the company reported second-quarter earnings that widely beat analyst expectations due to a strong showing from its commercial business.

On a quarter-over-quarter basis, Constellation was the sole utility in the list to record a positive change in market cap, which stood at $35.08 billion as of Sept. 29.

More utilities fared better on a year-over-year basis, with PG&E Corp. leading the pack with a 29.6% gain. Other companies posting year-over-year market cap gains included Exelon Corp., Public Service Enterprise Group Inc. and Edison International.

S&P Global Commodity Insights produces content for distribution on S&P Capital IQ Pro.