UnitedHealth Group Inc. (NYSE:UNH) announced Monday it has agreed to purchase 90 percent of Amil Participações SA, the Brazilian health benefits and health care services provider. The deal is valued at $4.9 billion.

The move gives the largest health insurer in the U.S. a firm foothold in Latin America’s largest health insurance market.

UnitedHealth, based in Minnetonka, Minn., said in its announcement Monday that Brazil is “under-penetrated in managed care.” Amil provides benefits to about 5.9 million Brazilians, partly through a network of 3,300 hospitals and 55,000 clinics, according to the company's website. The company reported $4.4 billion in revenue last year, according to Bloomberg.

UnitedHealth provides services in 70 countries, but a representative told the Associated Press that the company’s international operations make up a small part of its total business. The insurer covers 35.9 million people in the U.S.

Brazilian billionaire Edson de Godoy Bueno will hold 10 percent of Amil and will become the largest individual investor in UnitedHealth Group with a seat on the board as a result of the deal.

"Our merger with UnitedHealth Group will allow us to bring advanced technologies, its tradition of innovation initiatives services and clinical programs to further enhance health in Brazil," Bueno said in the Amil statement announcing the deal.

Shares of United Health closed Friday at $57.13.