A spokeswoman for the group said that the company will retain a sales office at the London site, which is leased, until such time as it finds a new London base.
The move will occur in early May, and also moving to the site will be Polestars data centre, based in Watford, and staff at an administration office in Stratford.
Polestars Watford-based pension centre will remain.
Polestar is also said to be on the brink of signing an order for a new 64pp MAN Roland web press.
It is believed the huge Lithoman machine is destined for the groups Watford plant, which already houses three 64pp machines.
Watford prints a number of long-run magazines and newspaper supplements including TV Times and Night & Day (Mail on Sunday).
This would be the second large web order for MAN Roland in the UK this year.
Story by Andy Scott
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