The United States Postal Service will announce a $2.5 billion dollar yearly loss tomorrow, ABCNews.com has learned.
But postal officials say it is unlikely to result in any increase in the cost of mailing a first class letter.
The price of a first-class stamp was raised one cent in May of this year, to 42 cents, following an even larger loss last year of $5.1 billion.
Postmaster General John E. Potter has said no further increase in the cost of first class stamps would be considered until May, 2009 at the earliest.
Postal service officials say the loss this year, and the year before, was due largely to a Congressional mandate requiring the Postal Service to pre-pay $5 billion in retirement benefits for postal workers.
But for that requirement, say officials, the Postal Service would have posted a $2.5 billion profit this year.