Oil prices eased on Friday after the U.S. central bank warned of a weakening global economy and on signs that the world’s biggest crude producers would keep pumping at high levels to maintain market share. The Federal Reserve decided against raising interest rates from historic lows on Thursday, saying uncertainty about global economic growth had forced its hand. “The price decline is partly due to the U.S. stock market performance last night and partly due to the generally bearish fundamental picture,” said Tamas Varga, oil analyst at brokerage PVM Oil Associates in London.