Once the acquisition completes, PrintWeek understands the plan would be for Polestar and River to work together on specific retailers and brands to create a full multi-channel service offering.

However, contrary to reports, there appear to be no plans to merge the two businesses.

PrintWeek understands that Nicola Murphy will remain as chief executive of River Group, which creates content for clients including Honda, Superdrug and the Co-operative Group's grocery arm.

Polestar is understood to be preparing an announcement that will be released once the deal closes.

Sun European parners acquired Polestar in 2011 and has since supported its acquisition of rival web offset printer Goodhead Group and its £50m investment in a new press hall in Sheffield.

This story will be updated if the deal is confirmed.