Wanda, founded in 2006, took net sales of £2.2 million last year and has a client roster that includes Turkcell, L’Oreal, Nestle and Unilever.
Wanda and Manajans J Walter Thompson Turkey will continue to operate independently and invest in new technology and innovative projects.
Manajans Thompson was bought outright by JWT in 2012. The WPP-owned agency had owned a minority stake in Manajans since 1985.
A statement from WPP explained: "Turkey is one of the next 11 growth economies where WPP companies (including associates) generate revenues of over $1 billion and employ over 10,000 people.
"In Turkey itself, WPP companies (including associates) generate revenues of around $120 million and employ approximately 1,300 people."