The FTSE 100 has recovered from an early fall after the US's weekend bombing of Iranian nuclear sites.
An hour into trade, London's blue chip index is less than a point down at 8,774.07.
BP PLC (LSE:BP.) and Shell PLC (LSE:SHEL, NYSE:SHEL) are among the early risers as oil briefly jumped above $80 a barrel on potential supply constraints as Iran takes action following the weekend's events.
easyJet PLC (LSE:EZJ) is leading the decliners on concerns about travel disruptions.
In company news, Assura Group (LSE:AGR) has agreed to a takeover by Primary Health Properties PLC (LSE:PHP, OTC:PHPRF), which has raised its offer to £1.79 billion to edge out a rival bid by private equity groups KKR and Stonepeak.
And another FTSE 250 deal has been agreed, but this one will see instrumentation and controls engineerSpectris PLC (LSE:SXS) taken private for £3.8 billion by US private equity group Advent.