NextEra Energy Inc. became the first U.S.-headquartered power company to surpass $100 billion in market capitalization.
During the third quarter, NextEra recorded a 13.8% quarter-over-quarter increase in market cap to $111.63 billion, cementing its first-place spot on the list of the top 20 U.S. electric and multi-utility companies by market cap as of Sept. 30, according to data compiled by S&P Global Market Intelligence.
The Juno Beach, Fla.-headquartered company, which closed its $1 billion acquisition of an underwater transmission cable system in California in July, is considering merging Gulf Power Co. with its flagship utility, Florida Power & Light Co. NextEra purchased Gulf Power from Southern Co. in January, in a deal valued at about $4.35 billion in cash, with the assumption of about $1.30 billion in debt.
NextEra was followed by Duke Energy Corp. with a market cap of $69.84 billion and Dominion Energy Inc. with a market cap of $65.11 billion as of Sept. 30.
Overall, the U.S. utility companies' market capitalization grew to $776.79 billion at the end of the third quarter, up from $711.35 billion in the second quarter, with no company recording declines in their market cap. Of the total, 16 utilities retained their rankings on the list and nine utilities posted double-digit percentage increases in their market cap, compared to the second quarter.

California utility Edison International posted the steepest gain in market cap of 23% to $27.01 billion, improving its ranking on the list by three spots to 13th position from 16th position. Entergy Corp. improved its ranking by one position to the 16th spot, after posting a 14.3% gain in market cap to $23.33 billion.
Other companies recording double-digit percentage increases included FirstEnergy Corp. at 14.5%, WEC Energy Group Inc. at 14.1%, Eversource Energy at 12.9% and Southern Co. at 12.2%.
DTE Energy Co. and PPL Corp. were the only two utilities that saw their rankings slip; they dropped two spots to the 15th and 17th positions, respectively. DTE Energy posted a 4% quarter-over-quarter increase in market cap to $24.37 billion, and PPL saw its market cap increase 1.6% to $22.74 billion.

In the third quarter, S&P 500 utility indexes outperformed the broad S&P 500 index, with the S&P 500 Electric Utilities Sub Industry index posting a total return of 10.4%, followed by the S&P 500 Utilities index with a 9.3% gain and the S&P 500 Multi-Utilities index with a 7.9% gain. The S&P 500 index saw a total return of 1.7%.
