The Labor Department said on Wednesday its Consumer Price Index increased 0.2 percent last month as energy prices rebounded, after edging up 0.1 percent in August.
In the 12 months through September, the CPI increased 1.2 percent, the smallest gain since April. It had advanced 1.5 percent in August.
Economists polled by Reuters had expected consumer prices to rise 0.2 percent last month and increase 1.2 percent from a year ago.
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The benign inflation environment should allow the Fed to stay the course on its monthly bond purchases as it tries to stimulate the economy through low interest rates.