Photo: The Canadian Press. All rights reserved.

In this Tuesday, June 26, 2012, file photo, Tressa Miller, right, helps military veteran Roger Porter, of Detroit, with resume career counseling in Detroit. THE CANADIAN PRESS/AP, Paul Sancya

The number of Americans seeking unemployment benefits plunged last week to the lowest level in four years, a hopeful sign for the U.S. job market.

The U.S. Labor Department says weekly applications for unemployment benefits dropped 26,000 to a seasonally adjusted 350,000, the lowest level since March 2008. The four-week average fell to 376,500.

When applications consistently fall below 375,000, it generally suggests hiring is strong enough to reduce the unemployment rate.

A revival of U.S. employment is considered critical to improved trade with Canada, which supplies its neighbour with resources, services and manufactured products.

But the decline in U.S. claims last week was partly due to temporary factors.

Automakers are limiting their usual summer shutdowns to boost production, resulting in fewer temporary layoffs than is normally the case.