PORTLAND – Uncertainty in the bond markets is delaying a passenger terminal expansion for Maine’s busiest airport.

The Portland International Jetport is putting a four-story addition to the passenger terminal on hold for a year. Director Paul Bradbury says work on the 160,000-square-foot addition was supposed to begin in spring of next year. Instead, it’s delayed until the spring of 2010.

A parking lot expansion, meanwhile, is continuing. The five-story parking garage with space for 1,000 vehicles will be partially open in time for the Thanksgiving holiday. Bradbury said the expansion will accommodate projected growth through 2015.