Energy stocks fell late Thursday afternoon, with the NYSE Energy Sector Index down 0.3% and the State Street Energy Select Sector SPDR ETF (XLE) decreasing 0.8%.

The Philadelphia Oil Service Sector Index was rising 0.9%, and the Dow Jones US Utilities Index was up 0.8%.

President Donald Trump said Thursday on Truth Social he has cancelled previously announced strikes on Iran tonight as "final points" of a deal have been, "in both concept and great detail, approved by all parties involved." He said the time and place of a deal signing between the nations will "be announced shortly."

Front-month West Texas Intermediate crude oil fell 2.4% to $87.83 a barrel, and the global benchmark Brent crude contract dropped 2.7% to $90.60 a barrel. Henry Hub natural gas futures shed 2.9% to $3.09 per 1 million BTU.

In corporate news, Black Hills' (BKH) pending merger with NorthWestern Energy (NWE) has an underappreciated strategic value as the combination will likely offer larger scale, stronger balance sheet, and wider jurisdictional diversity, BofA said in a note. BofA upgraded Black Hills to buy from neutral and increased the company's price target to $78 from $76. Black Hills shares rose 1%.