The chairman of the postal Board of Governors, Mickey Barnett, cites the "precarious financial condition" of the agency and the uncertain prospects for postal overhaul legislation in Congress.
The agency expects to lose $6 billion this year.
Wednesday's request for the increase in stamp prices must be approved by the independent Postal Regulatory Commission.
The Postal Service said it would ask for adjustment to bulk mail rates in a filing with the commission Thursday. No details were immediately provided.
Media and marketing businesses say a big increase in rates could hurt them and lower postal volume and revenues.
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