The price of oil has reached a new high for 2009, continuing its recent rise on the back of a weak US dollar and strong US company results.
The BBC reports US crude settled up $US1.08 per barrel at $US79.61 in New York trading.
London Brent crude rose 78 cents to $US77.77 per barrel.
Oil prices surged last week, as encouraging US bank results fuelled optimism for the global economy.
Analysts said the short-term direction of oil would depend on the dollar and the next round of corporate results. There was much caution that price rises in recent days could easily be reversed.
The dollar lost more ground against the euro in early trading on Monday, falling to $US1.4940, just below a 14-month low of $US1.4967 last week.