Below are some key facts about the healthcare system in Brazil:

*As of June 2012, Brazil had around 48.7 million people covered by private health insurance (with or without dental coverage) and 17.6 million beneficiaries of dental plans only - a coverage ratio of 25.5 percent of the population for health insurance plans and 9.2 percent for dental plans.

*From 2004 to 2008, the number of people with private health insurance in Brazil grew at an annual rate of nearly 5 percent. In 2009, after the global financial crisis, growth slowed to 3.3 percent, but jumped to 8.2 percent in the following year, helped by domestic measures to stimulate the economy.

*Last year, the Brazilian private health insurance sector expanded 3.9 percent, above Brazil's GDP expansion of 2.7 percent.

*Health insurance companies in Brazil, including those that only offer dental plans, made about $41.6 billion (84.5 billion reais) in revenue in 2011.

*Amil has more than 5 million clients in Brazil and owns 22 hospitals and 50 clinics. It says it has the largest network among health providers in Brazil, with 44,000 medical doctors, 3,300 hospitals, 11,000 clinics and 12,000 laboratories.

*Amil forecast revenue of $5 billion in 2012, a 15 percent increase from the previous year.

*The burgeoning business is also attracting more scrutiny. Last week, Brazil's health insurance regulator suspended for three months sales of 301 insurance plans managed by 38 providers, saying the companies were taking too long to provide surgeries, lab tests and doctor appointments to their clients.

Sources: Brazilian health regulator ANS, Amil

(Compiled by Walter Brandimarte and Debra Sherman. Editing by Andre Grenon)

Stocks treated in this article : Amil Participacoes SA, UnitedHealth Group Inc.