The number of Americans filing new claims for unemployment benefits rose last week, a potentially worrisome sign for the economy although the level still pointed to ongoing healing in the labour market.

Other data showed prices for US imports and exports fell in June for the fourth straight month, hit by cooler economic growth worldwide.

Initial claims for state unemployment benefits increased by 16,000 to a seasonally adjusted 360,000, the labour department said.

"It's a little bit worrisome," said Russell Price, senior economist at Ameriprise Financial Services Inc in Troy, Michigan. Still, the reading was likely clouded by seasonal factors.

The labour department can have a tough time seasonally adjusting claims in early July because many factories shut down during that period for retooling, but the scheduling for the shutdowns varies from year to year.

Even with the increase, the number of layoffs remains in the range of levels seen over the last year, and is consistent with a continued drop in the unemployment rate.

"The labour market has been doing pretty well," said Joshua Dennerlein, economist at Bank of America Merrill Lynch in New York.

The US labor market has shown signs of strength in recent weeks, with 195,000 jobs added to payrolls in June. This has cemented expectations the US Federal Reserve will start winding down its massive stimulus program as early as September.

The four-week moving average of new claims, which smooths out some seasonal volatility, increased by a more modest 6,000 to 351,750.

Some investors took the data as a sign the Fed might delay plans to reduce its bond-buying program aimed at spurring more job growth.

In a separate report, the labour department said export prices fell by 0.1 per cent last month. The drop probably reflects weakness in global demand which has been hit by Europe's debt crisis and slowing growth in China.

Import prices slipped 0.2 per cent last month, dragged down by another month of declining costs outside of the fuels category.

Reuters