Humana Inc posted a huge gain in first-quarter profit on improvement in its Medicare health plans for seniors, and the insurer raised its full-year earnings forecast.

The large provider of Medicare plans became the latest U.S. health insurer to easily surpass Wall Street profit forecasts for the latest quarter, even as shares remain pressured by fears over health care reform.

Net income rose to $205.7 million, or $1.22 per share, from $80.2 million, or 47 cents per share, a year earlier, when its Medicare business suffered.

Analysts on average had expected profit of $1.14 a share, according to Reuters Estimates.

Revenue rose 10.8 percent to $7.71 billion.

Humana posted pretax income of $166.1 million in its government segment, which includes Medicare, compared with a $3.2 million loss a year earlier. Lower claims expense in its prescription drug plans and implementation of premiums in its full-service Medicare Advantage plans helped results.

Humana's Medicare Advantage membership stood at 1.47 million at March 31, up 16 percent from a year earlier.

In its commercial segment serving employers, Humana reported pretax earnings of $127.7 million, compared with $127.2 million a year earlier.

Louisville, Kentucky-based Humana forecast full-year earnings of $6.10 to $6.20 per share. It had previously projected $5.90 to $6.10.

The higher forecast reflected improved performance in its government segment, partially offset by lower expected investment income, Humana said.

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