The financially struggling U.S. Postal Service says it plans to stop delivering mail on Saturdays, but continue delivering packages six days a week.

In an announcement scheduled for later Wednesday, the service is expected to say the cut, beginning in August, would mean a cost saving of about $2 billion annually.

The move accentuates one of the agency's strong points -- package delivery has increased by 14 percent since 2010. The delivery of letters and other mail has declined with the increasing use of email and other Internet use.