U.S. import prices rose 1.3 percent in May, the Labor Department said on Friday, but the gain was powered by petroleum prices and underlying import price pressures were more muted.

Analysts had forecast import prices would rise 1.3 percent after a revised 1.1 percent rise in April, previously reported as a 1.6 percent increase. May's gain was the largest since a 1.4 percent advance in July 2008.

Recent declines in the dollar might press import prices higher and contribute to inflation, but year-over-year, import prices declined by a record 17.6 percent, indicating little threat of this at the moment.

The data still suggest a lurking inflation threat, but that's not likely to perturb the markets just yet given ongoing weakness in economic growth, said Action Economics in a note to clients.

On the other hand, there were signs that prices had arrested their prolonged slide in the face of the most severe worldwide economic slowdown in a generation, chiming with other evidence that a recovery may be drawing near.

Non-petroleum import prices rose 0.2 percent in May, the first increase since July 2008, although they were down a record 5.8 percent over the year.

The Labor Department said the increase in non-petroleum prices was driven primarily by a 0.6 percent increase in prices for non-petroleum industrial supplies and materials, also the first rise for that index since last July.

Higher prices for automobiles and for foods, feeds and beverages also contributed to May's overall increase in non-petroleum prices, the Labor Department said.

Export prices rose 0.6 percent in May compared with forecasts for a 0.4 percent gain. They rose 0.4 percent in April and are down 6.5 percent over the year.

Imported petroleum prices were up 8.3 percent in May, the fourth consecutive gain after bottoming in January, but are 51.4 percent lower over the year.

(Editing by Andrea Ricci)

Inflation