Brent sweet crude oil futures rose to as much as $83.27 a barrel.
Browsing: Brent crude oil
Brent crude futures rose to $80.41 a barrel, by 11:12am EDT (1512 GMT).
Worries that the escalating war in Syria could disrupt Middle East oil supplies pushed Brent to a six-month high above $117 in August.
Prices have dropped more than $10 a barrel since then and some analysts see further falls ahead