Portland-based Mac Air Group will begin construction Thursday on a $6 million facility that will allow the company to serve its growing number of international and domestic aviation clients.

The new 43,000-square-foot facility is the first development on the southeast side of the Portland International Jetport. When complete, Mac Air Group plans to add 15 permanent jobs to its current staff of about 60 people.

Company representatives and officials from Portland and South Portland will attend a groundbreaking ceremony at 10:15 a.m. Thursday at the airport.

The company, formerly Maine Aviation Corp., provides high-end aviation services such as aircraft maintenance services and hangar space. It also offers sales and charters of luxury aircraft.

The company has flown from the airport since 1959. It specializes in converting used 50-seat commercial jets into luxury, 16-seat private jets. The planes have a range of 3,000 nautical miles.