Chicago ? Bankrupt United Airlines said Friday it would lay off nearly 1,700 more employees, or about 2 percent of its work force, and shut down all of its U.S. ticket offices to slash costs.

The world’s No. 2 carrier has until Feb. 15 to cut costs significantly or it could lose the remainder of $1.5 billion in interim financing.

The bulk of the layoffs involve nearly 1,500 management and salaried employees whose nonunion jobs will be cut by Jan. 19.

“These changes are part of the process of creating a new business that is competitive, customer-focused and sustainable,” said Sara Fields, senior vice president.

United said it decided to close down the 32 ticket offices — all of them outside airports — based on customers’ increasing shift to buy tickets online or by telephone.

The ticket office closings, effective Jan. 28, will result in the loss of an additional 188 jobs. Those employees are represented by the Machinists’ union.

United spokesman Jeff Green put the total number of jobs being cut at about 1,700. The airline, which employed about 100,000 people before the 2001 terrorist attacks, now has about 83,000.

No dollar figure was given for the amount that will be saved by the moves.

United, which filed for federal bankruptcy protection Dec. 9, warned earlier this week that significant layoffs could be expected. The carrier says it must reduce wages by $2.4 billion a year through 2008, and four of its five unions are voting on whether to ratify steep pay cuts.

The company is expected to report an annual net loss exceeding $2 billion for a second straight year.