Shares of oil and gas companies in both U.S. and European markets weakened on the news that the U.S. military had paused a two-week campaign of strikes on Iran and that Iran signalled it would suspend its own attacks while the pause remains in effect. Investors reacted to the reduced near-term risk of a broader regional conflict by selling energy-related stocks and pushing crude prices lower.
In U.S. trading, the reports coincided with declines among major producers. Chevron and Exxon Mobil each dropped about 2.5%, ConocoPhillips slid 3.1% and Devon Energy fell 3% by 04:42 ET (08:42 GMT). Oilfield services firms also moved lower, with SLB down about 1.3% and Halliburton slipping 1.8%. Occidental Petroleum and Diamondback Energy fell 3.7% and 2.7%, respectively.
European energy names recorded still steeper falls, dragging the region's oil and gas index roughly 2% lower. BP fell 3.6% and Equinor declined 5.4%. Var Energi, Eni and Maurel & Prom each lost more than 4% on the session.
Other European integrated and upstream companies were also weaker: Neste, Shell and Repsol slid by more than 1% each, Aker BP declined 3.2%, while TotalEnergies and OMV were down around 3% each. Portugal's Galp dropped 3.2% after a combination of second-quarter results and news of an acquisition of a wind portfolio compounded selling pressure.
The selloff in equities tracked a sharp fall in oil markets. Brent crude futures fell 6.7% to $90.24 a barrel after the pause was announced, reflecting reduced immediate risk premia that had been built into prices earlier in the flare-up.
U.S. officials said diplomats were attempting to give peace talks "some space," after a China-led effort to restart stalled negotiations in Pakistan. Iran has also held back from further regional operations in recent days and indicated it would reciprocate the halt so long as the pause continues.
That respite did not eliminate all conflict-related incidents over the weekend. Saudi forces struck Iran-backed Houthi targets in Yemen in response to the group's recent attacks on Red Sea shipping, signalling that regional tensions remain active. Separately, Ukraine's military reportedly struck an Iranian commercial vessel in the Caspian Sea, killing one sailor and injuring another; Kyiv said the ship was carrying military cargo supporting Russia's invasion, while Tehran described the strike as a "hostile and criminal act."
Market participants were encouraged by the temporary pause, particularly given earlier reports that the White House was considering a "massive attack" on Iran. Yet analysts warned that the path to a lasting settlement remains uncertain: negotiators still must resolve difficult issues including the future of Iran's nuclear program, the prospect of easing sanctions and Tehran's support for proxy groups across the region.
Strategic chokepoints remain a source of concern for energy markets. The Strait of Hormuz, through which roughly a fifth of global oil supply flowed prior to the recent spike in tensions, remains closed with the U.S. maintaining a blockade of the waterway. That status keeps a structural source of supply-side risk intact even as immediate hostilities are temporarily paused.
Investors will likely monitor any further diplomatic progress and signs of sustained reductions in regional military activity. For now, the pause prompted a sizable re-pricing across oil and gas names and crude futures, but several unresolved security and diplomatic issues mean volatility may persist.