Advertising and media giant WPP has taken a majority stake in The Volcano Group, a South African advertising and communications company.The acquisition, made by WPP's wholly-owned marketing communications agency Grey, "continues WPP's strategy of developing its services in fast-growing and important markets and sectors and strengthening its capabilities in digital media", the company said.Johannesburg-headquartered Volcano provides integrated marketing services covering traditional and digital advertising, PR, insight and social. Clients include Procter & Gamble, First National Bank, Sony and Consol Glass.Following the deal, Volcano will be rebranded as Grey Africa.WPP's digital revenues represented 35% ($6bn) of total group sales ($17.3bn) in 2013. The company continues to target a 40-45% contribution from the sector in the next five years.WPP, which already employs 26,000 people in South Africa, generated $500m of revenues from the country last year.BC