Oil prices fell on Monday, with cautious sentiment as financial markets fell last week and the dollar rose earlier this week.
This underscores concerns that growth may be slowing, particularly in emerging economies in Asia.
By 0616 GMT, global Brent crude futures were trading for the nearest month of 39 cents, or 0.5 percent, to $ 77.23 per barrel.
US WTI crude futures fell 28 cents, or 0.4 percent, to $ 67.31 a barrel from the previous close.
Investors are worried after heavy losses last week, while the rise in the dollar as a safe haven has put pressure on the purchasing power of emerging markets.
Eastport brokerage brokerage, based in Singapore, said share prices were falling amid the uncertainties in policy, high interest rates and disappointing earnings for some companies.
On the supply side, tensions remain in the oil markets ahead of imminent US sanctions on Iranian oil exports, which are due to come into effect next week.
It is expected to lead to tight supplies, particularly in Asia, which receives the bulk of Iranian crude shipments.
