Prices head for biggest weekly rise in more than 3 years

Commodities jumped on Friday, headed for their largest weekly gain in more than three years as base metals roared higher after Glencore pledged to slash zinc output and gold hit three-week highs after dovish Federal Reserve minutes. Surging metals offset a choppy oil market. Brent, the global benchmark, slipped on Friday under pressure from bargain hunting at the end of a big weekly increase.