Public relations firm Greentarget moved its headquarters to the Chicago Board of Trade's north tower, the company said. It moved in late November after signing an eight-year lease for the 9,200-square-foot 31st floor at 141 W. Jackson Blvd., the firm said. Thirty employees moved there from 6,600 square feet at 1 N. LaSalle St., the firm said. Occupancy in the 1.3 million square feet in the north and south towers is now 73 percent, up from 61 percent when Chicago-based GlenStar Properties and San Antonio-based USAA Real Estate bought the property in 2012, according to GlenStar Managing Director Christian Domin. Greentarget was represented by Jason Schulz, CEO of Chicago-based brokerage J. Rich Co. “The open atmosphere of the CBOT space provides a bright and energizing environment that fosters heightened collaboration and creativity among the Greentarget team,” Greentarget President John Corey said in a statement.