LONDON: Brent crude oil extended gains to rise over $1 on Tuesday, on worries about supply, even as euro zone worries sent other demand sensitive assets like equities lower.

By 0834 GMT, Brent was $1.06 higher at $104.70. Traders cited worries about sanctions-hit Iran struggling to maintain its production and the risk of supply being disrupted from Central Asian oil producer Kazakhstan, as pushing prices higher.