WASHINGTON (Reuters) -The U.S. Postal Service (USPS) on Friday finalized a plan effective Oct. 1 to slow down some first-class mail delivery as part of a plan to cut red ink. Postmaster General Louis DeJoy proposed in March to revise existing one- to three-day service standards for first-class mail. USPS said on Friday that 61% of first-class mail will remain at its current standard. USPS said in a notice published in the Federal Register the current standards require it “to rely heavily on air transportation, using air cargo transportation carriers and commercial passenger air carriers.” It added that the “basic logic of the changes is that the addition of one or two days to current service standards for First-Class Mail and Periodicals would enable the Postal Service to convey a greater volume of mail within the contiguous United States by surface transportation.” For the minority of first-class mail impacted “the standard would only change by one or two days (with most of such volume experiencing a one-day change),” USPS said. In June, the attorneys general of 20 states asked the U.S. Postal Regulatory Commission to reject plans to slow down some first-class deliveries, saying allowing that to happen could harm local governments’ ability to fulfill essential functions. DeJoy unveiled a plan in March to cut $160 billion in predicted losses over the next decade with the changes in service standards a central part. USPS has struggled with poor delivery performance over the past year, facing a huge boost in packages and staffing issues due to the coronavirus pandemic. Reporting by David Shepardson; editing by Diane Craft and Marguerita Choy Our Standards: The Thomson Reuters Trust Principles.