WASHINGTON - More Americans requested unemployment benefits last week, but the level remains near historic lows in a positive sign for the job market.

The Labor Department says applications for jobless aid jumped 20,000 to a seasonally adjusted 287,000. The less volatile 4-week average climbed 4,500 to 277,000.

Despite the increase, jobless claims have stayed below the key level of 300,000 for nearly 10 months. Any figure lower than that threshold often corresponds with monthly job gains in excess of 200,000. Applications for benefits are a proxy for layoffs, so the low level indicates that employers are keeping their workers and potentially planning to hire.

Unemployment last month held at a seven-year low of 5 percent. Employers have been adding a healthy 210,000 jobs a month so far this year.