NEW YORK (CNN/Money) - US Airways Group Inc. said Monday it would begin deferring payments on public debt related to some aircraft as the commercial carrier continues restructuring to revive the business.

US Airways, the sixth-largest U.S. air carrier, said last week that it would defer payments to some lessors and lenders of the aircraft, mostly older Boeing planes and planes that have already been grounded.

The Arlington, Va.-based carrier said it is negotiating with creditors to reduce and restructure existing loan agreements. US Airways said the payment deferrals do not reflect its cash position, and that it plans to continue paying its other day-to-day expenses and debts. It does not expect operations or customer service to be affected.

The airline also said Monday that it told the government which lenders have agreed to put up a $100 million "at risk" portion of a $1 billion loan. The at-risk portion would not be covered by a prospective $900 million federal loan guarantee that the airline applied for last month.

Moody's Investors Service cut its credit ratings on US Airways Group and its subsidiaries last week, and said it might cut them further, after the airline announced its unilateral decision to defer payments to lenders and lessors.  

--from staff and wire reports