MINNEAPOLIS — The U.S. Postal Service might close four mail-processing centers in Minnesota as part of a plan for nationwide cutbacks.

The four centers in Minnesota are the same ones that the Postal Service said in September it was studying for possible closure. They are in Bemidji, Duluth, Rochester and Waite Park. In addition, the Postal Service is studying possibly moving some or all of the Mankato processing center’s operations to Minneapolis.

Regional Postal Service spokesman Pete Nowacki says the plan isn’t final.

Nationwide, the agency plan would close 252 processing centers and slow first-class delivery next spring, because of steadily shrinking mail volume.

The Postal Service is planning $3 billion in reductions aimed at helping the agency avert bankruptcy next year.