The pan-European STOXX 600 slipped 0.4% to 625.83 by 0806 GMT, with all major regional indexes lower as rising US-Iran tensions darkened risk appetite.
Crude jumped more than 2.5% above $97 a barrel after hostilities escalated and Kuwait said its air defenses were intercepting hostile missile and drone threats.
Air France and Lufthansa each fell about 1% as higher energy costs pressured airlines, while most sectors traded in the red.
Technology stocks limited the broader decline: Soitec surged 16% after annual sales beat expectations, and Infineon and STMicroelectronics gained more than 2% each.
BT lost 2.5% after a report said Britain would oppose any move by Sunil Bharti Mittal to raise his stake, underscoring separate political pressure on European equities.
Is the UK's block on the BT deal a national security necessity or a new wave of economic protectionism?
With stagflation threatening Europe, can the ECB’s interest rate policy survive the escalating Middle East war?
Beyond military action, what long-term strategy can secure the world's most critical oil chokepoint from ongoing conflict?