U.S. producer prices moved up a steep 0.6 percent last month, above analysts' expectations, as energy, tobacco and vehicle prices all shot higher, a government report showed on Tuesday. Stripping out volatile food and energy costs, the Labor Department's producer price index, a gauge of prices received by farms, factories and refineries, rose 0.3 percent. Wall Street economists had forecast a 0.4 percent rise in April producer prices, and a 0.2 percent gain excluding food and energy costs. The higher-than-expected increases were likely to keep inflation worries alive in financial markets. Energy prices rose 2.1 percent last month, a bit slower than in March. If that gain were stripped out, producer prices would have risen just 0.1 percent.