WASHINGTON -- The House is slated to bring forward an extension of unemployment insurance benefits next week, according to two House Democratic aides.

The extension will offer an additional 13 weeks of benefits to jobless people living in states with an average unemployment rate of 8.5% over the last three months.

That would cover 75% of the U.S. population, one aide said.

The national jobless rate is 9.7%, although some states like Michigan have unemployment rates well into double digits. Most economists expect the national rate to keep rising into 2010, despite signs that the recession is ending. A recovery in the job market often lags behind a wider economic turnaround.

By some estimates, 400,000 long-term unemployed could see their benefits expire by the end of September, rising to 1 million by the end of the year.

The extension would be paid for by improvements in the way the program is administered, said one congressional staffer.

A House vote is likely Wednesday or Thursday.

A senior Democratic aide said Friday that assuming the House passes the legislation, the Senate would seek to take it up as quickly as possible.

An aide to Senate Minority Leader Mitch McConnell (R., Ky.) said Republicans wouldn't likely object as long as the extension does not increase the size of the federal budget deficit.

This would be the fourth time lawmakers have acted to offer greater federal assistance to the unemployed since the recession began. Benefits have been extended to 33 weeks for those in the hardest hit states, and the weekly benefit level has been increased by $25. With this latest extension, people living in states with higher than 8.5% jobless rates would receive a total of 46 weeks of benefits.

Write to Corey Boles at corey.boles@dowjones.com