Farfar, a Swedish shop acquired by Aegis in 2005, will launch in London next month as part of Isobar's global network, led by Niku Banaie as its vice-president of strategy.
It will comprise employees from its office in Sweden, as well as London hirings.
Farfar's founding partner Matias Palm-Jensen has been working with Mark Cridge, the chief executive of glue, to set up the UK base.
It is believed the opening is linked to Isobar's recent win of the Nokia global digital account. Farfar has worked with Nokia in its home market for a number of years.
Meanwhile, Aegis has restructured Isobar in the UK to increase links between the network's businesses under a new central management led by Andrew De Groose, the former managing director of the Isobar digital creative agency de-construct.
The move will give clients access to the Isobar agencies Anorak, de-construct, Diffiniti, glue London and Marvellous, along with the digital arms Carat and Vizeum.
De Groose plans to extend the offering of Isobar through acquisition, start-ups or by developing existing divisions.