Allen (pictured) is currently head of Robert Horne's Sign and Display division, and replaces Marchant who was recently named as PaperlinX's regional president for the UK and Ireland.
"His energy in driving through the radical re-organisation of Sign and Display so quickly has demonstrated that he is exactly the right man to lead Robert Horne forward," said Marchant.
Allen will be responsible for the Sign and Display division until a successor is appointed.
Marchant is to replace Martin Fothergill, who is to relocate to Melbourne to become group general manager for merchanting Australia in and New Zealand.
Have your say in the Printweek Poll
Related stories
Latest comments
"Is a pre-pack looming?"
"Many of us designers create artwork for mixed media campagins (such as print, social media, digital billboards). Keeping images in RGB and letting the RIP convert saves a lot of time and energy rather..."
"Excellent news on both productivity and sustainability; great to see Acorn investing to deliver a better outcome for both into the future. Well done 🙌🙌🙌"
Up next...
Norfolk business to appoint liquidators
Blackwell Print closes doors
Restructure to take place
Footprint picks up marketing expertise in new merger
OK! Beauty Box subs also on the up
Football and Taylor Swift boost Reach results
Applications open until 30 March