UnitedHealth Group Inc, the largest U.S. health insurer, raised its earnings forecast for the year and posted a quarterly profit that beat Wall Street estimates, helped by strength across its businesses.

The company raised its full-year adjusted earnings forecast to a range of $12.40 to $12.65 per share from a range of $12.30 to $12.60 per share.

Net earnings attributable to shareholders rose to $2.84 billion, or $2.87 per share, in the first quarter ended March 31 from $2.17 billion, or $2.23 per share, a year earlier.

Excluding items, the company earned $3.04 per share.

Total revenue rose 13.3 percent to $55.19 billion.

Analysts on average were expecting earnings of $2.89 per share on revenue of $54.86 billion, according to Thomson Reuters I/B/E/S.

The company's medical care ratio, or the percentage of premiums paid out for medical services, improved to 81.4 percent in the quarter from 82.4 percent last year.

A lower medical care ratio percentage is better for insurers.

(Reporting by Tamara Mathias in Bengaluru; Editing by Shounak Dasgupta and Anil D'Silva)