Shares of energy companies sank as Hurricane Laura barreled into the Gulf of Mexico.

U.S. benchmark oil prices ended at their highest levels in more than five months as Laura choked off the Gulf's offshore crude oil production and forced oil refineries along the Texas and Louisiana coasts to shut down. More than a third of the U.S.'s operable oil refineries are in the Gulf Coast region, according to the Energy Information Administration, prompting concerns that the storms could crimp gasoline production.

Laura strengthened into a hurricane Tuesday and is projected to make landfall near the Texas and Louisiana border late Wednesday.

Meanwhile, Exxon Mobil shares fell after the company was removed from the Dow Jones Industrial Average to make room for Salesforce.com. Amgen and Honeywell will also be added to the blue-chip index effective Aug. 31, replacing Pfizer and Raytheon, respectively. The changes were prompted by Apple's four-to-one stock split announced last month. Chevron will be the only energy stock in the DJIA. 


 Write to Amt Pessetto at amy.pessetto@dowjones.com