UPDATE 2-UnitedHealth in talks with Brazil's Amil -source

Oct 6 (Reuters) - UnitedHealth Group Inc is in talks to buy some or all of Brazilian insurer and hospital operator Amil Participacoes SA, according to a person familiar with the matter.

The deal, which could be announced as soon as next week, would give the biggest U.S. health insurance company a bigger foothold in a growing private-insurance market in the world's second-biggest emerging economy.

Amil, with a market capitalization of $4.47 billion, is the largest health insurer in Brazil.

UnitedHealth declined to comment on Saturday, saying it was company policy not to comment on rumors and speculation.

The company already does business in Sao Paulo, Brazil. It also operates in dozens of other countries, including China, India, Australia, Britain, France, Italy and Canada.

Other insurers such as Cigna Corp have been looking to foreign markets. Cigna signed several agreements recently to sell insurance in emerging markets, including India, and has expanded its presence in Brazil and China.