Health insurer UnitedHealth Group said it would buy a 90 percent stake in Amil Participacoes SA , Brazil's largest healthcare company, for about $4.9 billion in cash.

Amil provides health and dental benefits, hospital and clinical services and advanced care management resources to more than 5 million people, the companies said in a statement.

The deal is expected to slightly add to UnitedHealth's 2013 earnings per share, the companies said.

(Reporting by Esha Dey in Bangalore; Editing by Saumyadeb Chakrabarty)