Oil rose to a two-and-a-half-year high overnight, with Brent crude pushing above 120 US dollars per barrel.

It's prompted by rising geopolitical risks to supply and gaining expectations of growing demand after last week's supportive US economic data. Trading of US crude was choppier after posting a two-and-a-half-year high of above 108 dollars per barrel, "ahead" of the opening trading bell in New York.

Analysts and brokers say a possible US shift to tighter monetary policy limited US price gains, while the Brent market remained well supported by its proximity and the more immediate impact of Middle East and Libya supply threats. Brent has recovered after falling below 108 US dollars in the aftermath of Japan's March 11 earthquake and tsunami.