Subscriber content previewSEATTLE — The Port of Seattle announced Wednesday its selection of M.A. Mortenson of Portland to act as general contractor/construction manager for upgrades to mechanical equipment and systems in concourses B, C and D at Seattle-Tacoma International Airport. The port plans to issue separate preconstruction and construction contracts for the GC/CM delivery. The construction MACC is estimated at $215 million, and MACC negotiations may begin with preconstruction work still underway. A notice of an initial $7.5 million award to Mortenson ran in Wednesday's DJC.