Shares in US Airways ( UAIR.Q ) jumped Thursday after a court approved an extension of a federal financing arrangement. The judge handling the carrier's Chapter 11 case said the carrier could continue to use loan guarantees by the Air Transportation Stabilization Board through June. 30. The financing arrangement was due to expire Saturday. US Airways has been slashing costs and renegotiating labor agreements as it struggles to survive amid a touchy environment for airlines. High fuel prices, fare wars and excess capacity have been testing even the healthiest members of the sector. The $900 million loan guarantee takes pressure off of the airline's operating capacity. The carrier can use cash proceeds from the financing. The airline's management recently said the carrier hopes to emerge from Chapter 11 protection sometime this summer. It's the airline's second trip through bankruptcy court in two years. Shares rose 9 cents, or 8.3%, to $1.17.