WASHINGTON (Reuters) - U.S. Postmaster General Louis DeJoy has agreed to pause planned further consolidation of the postal service's processing network after a bipartisan group of senators raised concerns about the impact on mail deliveries.

In a letter to Senator Gary Peters made public on Monday, DeJoy said he would pause the consolidation of processing facility operations until at least January 2025.

DeJoy said the change would delay USPS cost savings of $133 million to $177 million. Peters said he would keep pushing DeJoy and the USPS board of governors "for a plan that won't interfere with critical mail service."

DeJoy said there were ongoing reviews of operations at about 60 of 427 processing plants nationwide. DeJoy in his letter promised not to move forward with further consolidation without advising Congress "and then only at a moderated pace of implementation."

There has been mounting anger in Congress about changes that USPS has said are necessary to cut projected financial losses. Some lawmakers have raised concerns about closing a processing center in one state and shifting processing to another state.

Last week, 26 senators in a letter led by Peters and also signed by Susan Collins, Shelley Moore Capito, Jon Tester, Jeanne Shaheen and others, urged USPS not to make "irrevocable changes to its processing and delivery network."

DeJoy last week defended USPS's 10-year restructuring plan.

"This massive and complex evolution includes correcting for decades of haphazard decision making and neglect to our physical infrastructure network," DeJoy said, adding USPS knows it must make improvements "within the time limits we have for survival."

USPS in November reported a $6.5 billion yearly net loss as first-class mail fell to the lowest volume since 1968.

Last month, the Postal Service said it wanted to raise the price of a first-class mail stamp to 73 cents from 68 cents, effective July 14, the latest in a series of price hikes. USPS on Friday said it is seeking an average 25% price hike for high-volume shippers to enter packages for regional delivery.

(Reporting by David Shepardson; Editing by Chris Reese and Tomasz Janowski)

By David Shepardson