Health insurer Humana Inc is reducing its workforce by about 1,400 jobs, or 5 percent, during 2010 to align the size of the company with its lower membership.

The company plans to cut 2,500 positions, but add 1,100 jobs in growth areas, such as medical-cost containment capabilities, pharmacy management and specialty products.

Humana follows rival health insurers, such as Aetna Inc , in cutting jobs by similar amounts. Commercial membership in plans that serve employers are being pressured by high unemployment.

Humana's enrollment stood at nearly 10.3 million at the end of 2009, down 11 percent from the end of 2008.

Earlier this month, the company projected growth of 240,000 to 260,000 members in its Medicare Advantage plans in 2010, offset by expected declines of 160,000 to 180,000 in its commercial plans and of 50,000 to 100,000 in its standalone Medicare prescription drug plans.

This regrettable but necessary reduction in our workforce is a direct result of Humana's need to align the size of our company with that of our membership, Humana Chief Executive Officer Mike McCallister said in a statement.

Louisville, Kentucky-based Humana, one of the largest U.S. providers of Medicare plans for the elderly, previously said it planned to achieve $100 million in administrative cost savings this year and another $100 million next year.

Humana backed its 2010 earnings forecast of $5.15 per share to $5.35 per share, and said the workforce changes are not anticipated to lead to any changes to its prior earnings outlook.

Humana shares were up 34 cents, or 0.7 percent, at $46.35 in light premarket trading.

(Reporting by Lewis Krauskopf, editing by Gerald E. McCormick and Derek Caney)