Terms were not disclosed, but WPP said Quirk had revenues of about $13.3 million in its last fiscal year which ended in February.
Both WPP and Publicis Groupe have been acquisitive in South Africa in recent months, amid forecasts that the country will be one of the fastest-growing ad markets. ZenithOptimedia, for example, predicts that South Africa will be the eighth-fastest-growing country between 2013 and 2016.
Last month, Publicis Groupe bought South African media shop Applied Media Logic and earlier, bought search agency Synergize. Last November, WPP bought strategic marketing firm Cerebra. Earlier in the year its digital firm, VML -- part of the Y&R Group -- bought a majority stake in Native, which was rebranded Native VML.
In South Africa, WPP generates revenues of about $500 million in revenue and employs around 26,000 people. Across the continent of Africa, the holding company said it generates revenues of over $600 million and employs over 27,000 people.
Quirk was founded in 1999, employs 200 people and has offices in Cape Town and Johannesburg, among other cities. Outside of Africa, the shop has a London outpost. Clients include Distell, Capitec Bank, Woolworths, Caltex and Tyco.