The U.S. Postal Service will stop delivering mail on Saturdays but continue  to deliver packages six days a week under a plan aimed at saving about $2  billion, the financially struggling agency says.

In an announcement scheduled for later Wednesday, the service is expected to  say the Saturday mail cutback would begin in August.

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

Under the new plan, mail would still be delivered to post office boxes on  Saturdays. Post offices now open on Saturdays would remain open on  Saturdays.

Over the past several years, the Postal Service has advocated shifting to a  five-day delivery schedule for mail and packages -- and it repeatedly but  unsuccessfully appealed to Congress to approve the move. Though an independent  agency, the service gets no tax dollars for its day-to-day operations but is  subject to congressional control.

It was not immediately clear how the service could eliminate Saturday mail  without congressional approval.

But the agency clearly thinks it has a majority of the American public on its  side regarding the change.

Material prepared for the Wednesday press conference by Patrick R. Donahoe,  postmaster general and CEO, says Postal Service market research and other  research has indicated that nearly 7 in 10 Americans support the switch to  five-day delivery as a way for the Postal Service to reduce costs.