U.S. import prices spiked 2 percent in August as the cost of oil rose, the Labor Department said on Friday,

The increase, twice what analysts polled by Reuters had expected, was the fifth rise in the last six months. It followed a July drop of 0.7 percent.

Excluding petroleum, import prices increased a much milder 0.4 percent in August after falling 0.3 percent in July. Petroleum prices were up 10.5 percent and fuel import costs were up 9.8 percent -- both the sixth increases in the past seven months.

Import costs of foods, feeds and beverages also rose 1.7 percent in August, the largest advance since December.

Financial markets had little response to the report.

Earlier on Friday, the dollar fell to a one-year low against a basket of currencies, adding to upward pressure on future import prices and inflation.

Overall import prices dropped 15 percent from August 2008, and non-petroleum imports were down 6.5 percent.

Exports prices rose 0.7 percent in August, compared to falling 0.3 percent in July. Exports, excluding agricultural goods, rose 0.8 percent, the largest increase since July 2008. (Reporting by Lisa Lambert, Editing by Neil Stempleman)