Deutsche Post said in a statement that the restructuring, involving the winding up of DHL's domestic US air and ground operations, would cost about €3 billion ($3.9 billion).
The group "will focus its express business in the US on its core international competencies and exit the domestic air and ground express service in the country by the end of January," a statement said.
"The international express offering in the US will be maintained on today's levels and the region will remain an integral part of DHL's global Express network," it added.
Annual operating costs at its DHL U.S. Express unit "will be reduced from
$5.4 billion (€4.2 billion) to less than $1 billion."
The group said it would also cut other spending by another €1 billion by the end of 2010, updating a previous forecast of a €500 million reduction in 2009.
Deutsche Post, in which the government holds a 31 percent stake, nonetheless warned that it "will probably see a full-year reported net loss for 2008."
The Frankfurter Allgemeine Zeitung newspaper had said earlier on Monday
that Deutsche Post "assesses for this year alone at $1.3 billion, or €5 million a day, the loss recorded in the United States."
But the German logistics giant said its nine-month core earnings had gained 1.3 percent to €1.6 billion, on sales that rose by 2.3 percent to €40.5 billion. The share price jumped by 8.82 percent to €10.18 in midday trading, while the DAX index of leading shares had gained 3.17 percent overall.