Power utility NextEra Energy Inc. briefly surpassing oil giant Exxon Mobil Corp. as the most valuable U.S.-listed energy company last week underscores the multi-year shift from traditional toward renewable energy, brokerage UBS said on Oct. 5.

NextEra, which owns two electric companies in Florida serving more than 5.5 million customers, briefly overtook Exxon Mobil in Oct. 2's session and finished with a market value of $138 billion, just under Exxon Mobil's $139.5 billion market cap.

Oil and gas companies are facing increasing pressure from investors to reduce emissions, spend more on low-carbon energy and disclose the impact of their fossil fuel production on climate change.

UBS cited the example of Tesla eclipsing Toyota to become the world's most valuable car manufacturer, pointing to a shift toward a more sustainable "new economy".

Exxon Mobil has lost more than half of it market value in 2020 as the U.S. oil major struggles to cope with the effects of a pandemic-driven downturn in the energy industry.

The Irving, Texas-based company was also dropped from the blue-chip Dow Jones Industrial Average (DJIA) index in August in favor of cloud software developer Salesforce.com.

Exxon Mobil shares closed 2.3% higher on Oct. 5, taking the company's market capitalization to $142.7 billion. NextEra, which also closed up 2.4%, slightly lagged Exxon Mobil with a $141 billion in market capitalization.