Publicis Groupe, parent to 40-year-old Saatchi & Saatchi and Starcom MediaVest, is set to buy a controlling stake in Brazilian advertising agency, Talent.
It is understood that Publicis fended off competition from rival conglomerate WPP to secure the deal.
According to sources close to negotiations, the finer details have been agreed and Publicis are set to make a public announcement to the financial markets on Monday (13 September).
It is not known how much the deal is worth, but earlier speculation has valued it in the region of £200m.
A Publicis spokesperson refused to comment about any impending deal.
Publicis Groupe acquired Brazil's digital agency AG2 last month and the anticipated deal follows a concerted commitment by the group to invest in high-growth markets.
Announcing WPP's financial results last month, chief executive Sir Martin Sorrell alluded to "mad scrambles" to expand in China and Brazil, and referred to "particularly strong" revenue growth in Latin America.
In August, Publicis reported profits for the first half of the year leapt by 27.5% to €213m (£178m) which chairman and chief executive Maurice Lévy attributed in part to "investment in emerging markets".
Prior to the AG2 purchase Publicis Groupe had nearly 750 employees in Brazil. The group's brands in the country include Publicis Worldwide, Saatchi & Saatchi, Leo Burnett, VivaKi (Digitas, Razorfish, Starcom MediaVest Group, ZenithOptimedia), and MS&L Group.