Andreou left Polestar just under two years ago at the same time as chief executive Barry Hibbert cut overheads by introducing a leaner management structure.
Last month Polestar also parted company with chief operating officer Catherine Hearn when her role was made redundant. It's understood Andreou returned to the group shortly after Hearn's departure.
Andreou has made some immediate changes to the operating structure of the group. Polestar Sheffield managing director Andy Reynoldson, who has run the plant for just under four years, is moving to a newly-created group operational efficiency role, reporting to Andreou.
Reynoldson was credited with bringing stability to the gravure superplant after a tumultuous period when Polestar went through four MDs in five years at the flagship Sheffield site.
Phil Boynes, who had most recently been running Chantry, takes over from Reynoldson at the Sheffield gravure site and will also take over Reynoldson's other responsibilities for the single press Varnicoat operation.
Polestar Petty general manager Mark Walkington's remit has been expanded to include Polestar's other Yorkshire-based web offset plant, Chantry.
Bob Caley, who has been working for Polestar on a number of projects, has taken over as managing director at Nottingham-based Chromoworks.
PrintWeek also understands that Sun Capital Partners' Jack Knott, a managing director on its operations team, has become the lead director overseeing Sun's investment in Polestar.