Energy stocks were higher Monday afternoon, with the NYSE Energy Sector Index and the State Street Energy Select Sector SPDR ETF (XLE) rising 2.4%.
The Philadelphia Oil Service Sector Index was climbing 1.8%, and the Dow Jones US Utilities Index rose 1%.
Crude oil prices rose Monday after US President Donald Trump rejected Iran's counteroffer to end the war, extending uncertainty around oil flows through the Strait of Hormuz. Trump on Sunday described Iran's response to Washington's peace proposal as "totally unacceptable." The apparent US-Iran stalemate prolongs the effective closure of the Strait of Hormuz, the world's most important chokepoint for crude flows.
Front-month West Texas Intermediate crude oil rose 3.7% to $98.92 a barrel, and the global benchmark Brent crude contract was advancing 3.5% to $104.80 a barrel. Henry Hub natural gas futures gained 5.4% to $2.91 per 1 million BTU.
In corporate news, BP (BP) has a "second chance" to deleverage and restore financial health, supported by higher commodity prices that could put it on firmer footing in coming years, RBC Capital Markets said in a note. RBC upgraded BP to outperform from sector perform, while maintaining its 700 pence ($9.52) price target. BP shares were up 2.1%.