The Chicago-based carrier, an arm of United Continental Holdings Inc (UAL), informed employees Monday that jobs up for review included baggage handlers and gate and customer service agents at 28 airports that are not hubs, ranging from Atlanta to Anchorage. It has yet to make any decisions.

The potential outsourcing marks another step the carrier could take to help meet the goal it laid out in 2013 to cut costs by $2 billion annually. United said in an investor update Friday that it expects 2014 unit costs to increase up to 1.4% year-on-year, excluding fuel and other special charges.

The outsourcing review comes on top of plans announced in July to outsource more than 630 jobs.

“We need to ensure that our costs are competitive,” company spokesman Luke Punzenberger said.

United likely has faced pressure from Delta Air Lines (DAL), which has kept costs low because many of its workers lack union representation, according to a source familiar with the situation.

It was unclear how much United could save through outsourcing.

If the company decides to proceed, it would offer workers the option of transferring to jobs at other airports, based on seniority, according to Punzenberger. Furloughs or layoffs could result if workers decline the offers, he said.

The International Association of Machinists and Aerospace Workers, which represents those potentially affected by the review, learned several months ago that the carrier had asked contractors to submit proposals to perform ground handling work at several stations, union official Rich Delaney said in a bulletin posted on the union’s website over the weekend.

Now that United has notified the IAM officially of its review, it will enter negotiation with the union to see how it could retain workers within the airline. The Wall Street Journal reported that the union plans to meet with United on Tuesday.