The continued rise in energy stocks lifted UK shares at the open on Friday, but not by enough to prevent a weekly decline that was sparked by an escalation in the Middle East conflict.
The blue-chip FTSE 100 was up 0.1% by 0720 GMT, while the mid-cap FTSE 250 moved 0.4% higher.
However, both indexes look set to register weekly declines of 0.4% and about 2%, respectively.
Heavyweight oil and gas shares advanced 0.8%, rising for the sixth consecutive session in tandem with oil prices as the Middle East conflict raised worries about disrupting supply.
The personal goods index led sectoral gains with a 2% rise, while the broader aerospace and defence index was the bottom performer, losing 0.5%.
FTSE 100 rises on upbeat energy, metal stocks
Among individual stocks, Watches of Switzerland Group added 1.9% on its plan to buy Hodinkee, a digital content provider for luxury watch enthusiasts.
In terms of economic data, the US nonfarm payrolls report due later will take centre stage later in the day, though recent data showing continued strength in the labour market and impressive services sector activity implies there is little to be nervous about heading into the release.