U.S. import prices recorded their biggest decline in nearly 2-1/2 years in November as the cost of petroleum products tumbled, suppressing imported inflation pressures.

The Labor Department said on Thursday import prices dropped 1.5 percent last month, the largest decline since June 2012, after falling 1.2 percent in September. November marked the fifth straight month of declines in import prices.

Economists polled by Reuters had forecast import prices dropping 1.8 percent last month. In the 12 months through November, prices fell 2.3 percent.

Brent crude oil prices have tumbled to near five-year lows as faltering global growth undercuts demand. An increase in shale production in the United States has reduced the nation's dependence on foreign oil.

A strong dollar is also helping to keep imported inflation subdued.

Imported petroleum prices fell 6.9 percent in November, the biggest drop since June 2012, after declining 6.4 percent the prior month. Imported food prices fell 0.4 percent.

Import prices excluding petroleum fell 0.3 percent last month. They had slipped 0.2 percent in October.

The Labor Department report also showed export prices fell 1.0 percent in November after dropping 0.9 percent in October. In the 12 months through November, export prices fell 1.9 percent.