T-Mobile USA will pare 900 jobs, its second round of cuts in two months, following 10 consecutive quarters of contract user losses, even as some rivals are boosting their customer rolls.

T-Mobile, with about 36,000 employees, in March said it would trim 1,900 jobs and close seven call centers to help preserve funds for a $4 billion network upgrade to a high-speed mobile broadband network known as 4G LTE.

The Bellevue, Wash., company lost 510,000 of the lucrative contract users last quarter, which it said was partly due to it not yet offering the Apple Inc. iPhone.

The carrier continues to wrestle with the fallout from the failure of its deal to be taken over by AT&T Inc. for $39 billion last year. T-Mobile put strategic plans on hold for nearly a year, while competitors sought out new wireless airwaves, and the carrier has said that it doesn't expect to be net positive on contract customer gains until at least 2013.

"We are restructuring the organization and optimizing operations so that we can make critical decisions better and faster," the company said in an e-mailed statement. "By reducing our cost structure and streamlining operations, T-Mobile will be able to invest in areas where we anticipate the strongest return."