UnitedHealth Group Inc posted a much higher-than-expected second-quarter profit increase on Tuesday, helped by results in its government health insurance plans for elderly and low-income Americans, and the company raised its full-year forecast.

Net income at the largest U.S. health insurer by market value rose to $1.12 billion, or 99 cents per share, from $859 million, or 73 cents per share, a year earlier.

Analysts on average expected 75 cents per share, according to Thomson Reuters I/B/E/S.

UnitedHealth kicked off what is expected to be a strong second-quarter reporting season for health insurers. However, Wall Street enthusiasm for the industry is likely to remain muted as investors question whether its performance will be sustainable under the new U.S. healthcare reform law.

(Reporting by Lewis Krauskopf; Editing by Lisa Von Ahn)