WASHINGTON — The Postal Service has narrowed the number of offices facing possible closure to 413.

Struggling with a sharp decline in mail volume caused by the recession and the movement of traditional mail to the Internet, postal officials say the agency could have a deficit as large as $7 billion this year.

Being on the list doesn't guarantee closing.

Currently the post office has about 37,000 retail outlets across the country and Postmaster General John Potter has said he wants to keep as many open as possible.

In addition to losses caused by reductions in mail volume, the post office is required to place $5 billion annually in an account to prefund the costs of medical care for retirees.

The post office also has suggested reducing mail delivery from six to five days a week.