Oil prices rose on Friday after hitting fresh three-year highs in the previous session, as weakness in the dollar continued to underpin prices for a weekly gain. Brent crude futures settled up 10 cents, or 0.14 percent, at $70.52 per barrel. On Thursday, the contract climbed to as high as $71.28, its highest since 2014. US West Texas Intermediate (WTI) crude futures closed at $66.14 a barrel, up 63 cents, or nearly 1 percent. On Thursday, they also reached their highest since December 2014, at $66.66. Brent posted a nearly 3 percent weekly gain, while WTI reached a weekly gain of 4 percent. Both contracts strengthened after support from a weakening dollar, which hit three-year lows against a basket of currencies. The US economy didnt grow as quickly as many economists had hoped, according to numbers released Friday by the Commerce Department. The US economy growth rate in the last quarter of last year was 6.2 percent year-on-year, compared to 2.3 percent a year in the third quarter, while analysts expected the GDP to grow by 3 percent. In London, Brent crude rose by one cent, or 0.01 percent to 43.70 dollars a barrel. US energy companies added 12 oil rigs this week, the biggest weekly increase since March, as crude prices hovered near their highest levels since 2014. Drillers boosted the oil rig count to 759 in the week to Jan. 26, the highest level since September, General Electric Co’s Baker Hughes energy services firm said in its closely followed report on Friday