NEW YORK: Oil prices edged up about 1 per cent to a three-week high on Friday on expectations additional sanctions on Russia and Iran could tighten supplies, while lower interest rates in Europe and the US could boost demand for the fuel. Brent futures rose 67 cents, or 0.9pc, to $74.08 a barrel by 10:55am EST (1555 GMT). US West Texas Intermediate (WTI) crude rose 79 cents, or 1.1pc to $70.81. Both were headed for their highest closes since Nov 22. For the week, Brent was headed for a 4pc gain and WTI a 5pc advance.