United Airlines cutting more than 600 jobs

United Airlines announced plans Thursday to cut more than 600 jobs in an attempt to curb costs while it reduces flying.

A 6 percent cutback in management and administrative positions will occur in February, United Continental Holdings President and CEO Jeff Smisek said during a conference call where he and other top executives announced disappointing fourth-quarter and 2012 financial performance.

Smisek declined to say where the layoffs will occur, but the bulk of its administrative and management workforce is at the Chicago headquarters. A United spokeswoman said systemwide reductions will also affect positions in Houston, where the carrier operates its largest hub at Bush Intercontinental Airport and employs about 17,000 people.

Volunteers sought

In a letter to employees Thursday morning, Smisek said "a portion" of the reductions early next month "will come from a voluntary program, as we try to minimize involuntary reductions."

The letter also noted a 7 percent reduction in the number of top executives.

Spokeswoman Megan McCarthy said United cut four senior officers in December, out of about 50 at the company. The company employs

about 84,000 people worldwide.

Loss of $723 million

Thursday's layoff announcement came as United reported a loss of $723 million for last year — which compares with an $840 million profit in 2011 — because of costs related to its merger with the former Continental Airlines, and because of Hurricane Sandy, which reduced revenue by about $140 million. United plans to reduce flights this year, which is one reason for the job cuts.

The quarterly performance, however, slightly exceeded analysts' expectations thanks to stable fuel prices.

During Thursday's conference call, Smisek described 2012 as "the toughest year" of the merger integration but promised smoother operational and financial sailing in 2013.

He touted new products and services, including satellite-based WiFi on 300 long-haul jets.

The Associated Press contributed to this report.