Saturday mail delivery and unprofitable branches will have to go, he told the Washington Post.
The post office lost an estimated $6 billion on earnings of $68 billion in the fiscal year that ended Thursday.
It was the third consecutive loss year as customers increasingly paid bills, shopped and communicated online. Letter carriers delivered about 170 billion pieces of mail in fiscal 2010, about 7 billion fewer than last year, Potter said.
In just the past week, regulators denied the Postal Service's bid to raise stamp prices in January by 2 cents, and Congress decided not to reduce a $5.5 billion payment the agency must make for health benefits for retiring postal workers.
Potter wants the power to set delivery schedules and routes without interference from Congress. He also wants the agency to sell products and services besides boxes and stamps -- perhaps insurance, banking and cellphone services.
The Postal Service employs about 584,000 full-time workers, a drop of about 100,000 career positions in three years, Potter said.