Oil prices up slightly ahead of US election

Brent crude, which is used to price international varieties of oil, was up 63 cents to $108.36 on the ICE Futures exchange in London.

President Barack Obama is fighting for re-election in an extremely tight race with Republican challenger Mitt Romney. The uncertain outcome of the race for leader of the world's biggest economy has kept trading muted on financial and commodities markets this week.

The economic crisis in Greece is another factor traders are keeping an eye on. The Greek parliament holds a critical vote this week on a new austerity package that will impose further wage and benefit cuts.

Unions opposed to more austerity measures launched a 48-hour general strike on Tuesday. Police are bracing for violence in the debt-ridden country, now entering its sixth year of recession.

Lawmakers are expected to pass the measure. If not, Greece could lose vital rescue loans that have kept it afloat since May 2010 — raising the threat of bankruptcy and a euro exit.