Cushman & Wakefield Inc., one of the biggest real estate firms in the world, will be acquired by DTZ, a global real estate services firm backed by private equity firm TPG Capital, in a deal valued at about $2 billion.

The combined entity, which will operate under the Cushman & Wakefield brand, will have more than 43,000 employees, manage more than 4 billion square feet of property and boast revenue of more than $5.5 billion.

Brett White, DTZ’s executive chairman and a former chief executive of CBRE Group Inc., will be chairman and chief executive of the new company.

Exor SpA, the Italian company that owns 80.1 percent of Cushman & Wakefield, said in February it would put its stake up for sale. John C. Cushman, the Cushman’s L.A.-based vice chairman, was the single largest individual shareholder in the company. It was not clear whether his stake was part of the transaction and what role he would play in the new structure.

John Santora, Cushman & Wakefield’s North American chief executive, will become the chief operating officer and chief integration officer and DTZ’s Global Chief Executive Tod Lickerman will become president of the combined company.