ByJohn S. McClenahen Following three months in which it showed little or no change, the U.S. Labor Department's Consumer Price Index (CPI) advanced 0.3% in August. It was the largest increase in the closely watched measure of inflation since April's 0.5% increase. Higher costs for energy were a factor. Up 0.6% in August, energy costs increased for the second consecutive month -- though they clearly weren't the only culprit. The so-called "core" CPI, which excludes the relatively volatile month-to-month changes in prices for food and energy, rose 0.3% in August, its biggest monthly increase since April. Nevertheless, August's CPI rise "does not reflect a new upward trend," insists Karen Dexter, an economist at Merrill Lynch & Co., New York. She figures that minus gasoline, tobacco and apparel, the CPI was up just 0.1% -- and that minus apparel and tobacco, the core CPI also was up just 0.1%. "We still believe that inflation is a non-issue," states Dexter. Even with a higher rate of inflation, real earnings rose 0.3% from July to August of this year, other Labor Department data show. And between August 2001 and August 2002 average weekly earnings rose 3.1%, the department reports.