U.S. consumer prices rose 0.1 percent in March, a government report showed on Wednesday, matching economists' expectations for a tame reading and giving the Federal Reserve leeway to maintain ultra-low interest rates.

The Labor Department said the rising cost of fresh fruits and vegetables was the primary cause of the increase in the seasonally adjusted index. The index for food at home rose 0.5 percent, the largest gain since September 2008.

Excluding volatile food and energy prices, core CPI was unchanged in March after rising 0.1 percent in February. Economists polled by Reuters had expected a 0.1 percent rise in core CPI.

The energy index was unchanged, even though oil prices have been rising. Economists have been keeping a wary eye on energy prices for any sign that they could trigger a broader jump in inflation or compress consumer spending.

The Federal Reserve has pledged to keep its benchmark interest rate unusually low for an extended period as high unemployment slows the recovery from the worst recession since the Great Depression. The central bank has said a spike in inflation could change its mind, but Wednesday's CPI report showed price pressures remain subdued.

Over the last 12 months, CPI has increased 2.3 percent, before seasonal adjustment. Excluding food and energy, the core has risen just 1.1 percent over that period, the smallest increase since January 2004.

(Reporting by Emily Kaiser, Editing by Chizu Nomiyama)

Inflation