U.S. producer prices increased more than expected in May, leading to the largest annual gain in 3-1/2 years as the Middle East conflict boosted the cost of energy products, providing more evidence that inflation pressures were building up. The report from the Labor Department on Thursday and continued labor market resilience amid relatively low layoffs reinforced economists' expectations that the Federal Reserve would keep interest rates unchanged into 2027 and for the Federal Open Market Committee to ditch its easing bias at next week's policy meeting.