U.S. import prices recorded their biggest drop in nine months in August as a sharp decline in the cost of petroleum products eclipsed rising food prices, keeping imported inflation pressures subdued.

The Labor Department said on Friday import prices fell 0.9 percent last month after slipping 0.3 percent in July.

Economists polled by Reuters had forecast import prices declining 0.9 percent in August. In the 12 months through

August, prices dropped 0.4 percent.

Sluggish global demand and a relatively strong dollar are dampening imported inflation.

That and sluggish wage growth have translated into fairly benign domestic price pressures, which should buy the U.S. Federal Reserve a bit more time to maintain its very accommodative monetary policy stance.

Imported petroleum prices declined 4.4 percent in August, the biggest drop since last November, after falling 1.7 percent the prior month. Imported food prices gained 0.6 percent after rising 1.1 percent in July.

Import prices excluding petroleum slipped 0.1 percent in August. They were flat in July. The Labor Department report also showed export prices fell 0.5 percent in August after edging up 0.1 percent in July. In the 12 months through August, export prices rose 0.4 percent.