WASHINGTON The U.S. Postal Service on Tuesday reported a $6.5 billion net loss for the 12 months ending Sept. 30 with revenue down 0.4% to $78.2 billion as mail volumes continued to fall.

The Postal Service, which has been aggressively hiking stamp prices and is in the middle of a 10-year restructuring plan, said results were significantly affected by the impact of inflation on operating expenses.

The net loss was also impacted by accounting for its underfunded retirements caused by actuarial revaluation and discount rate changes.

Total operating expenses were $85.4 billion for the year, an increase of $5.8 billion, or 7.3%.

(Reporting by David Shepardson; Editing by Chris Reese)