Health insurer WellPoint Inc said quarterly profit, excluding huge gains from a sale, fell on lower enrollment and higher medical costs, but the results topped Wall Street estimates.

The largest U.S. health insurer by membership said enrollment in its more-lucrative, fully-insured employer plans came in 100,000 above its expectations, even as job losses continued to reduce its overall enrollment.

Fourth-quarter net income soared to $2.74 billion, or $5.95 per share, as it recorded gains from the sale of its $4.68 billion NextRx drug benefit business to Express Scripts Inc . That compared with net income of $331.4 million, or 65 cents per share, a year earlier, when investment losses dragged down results.

Excluding the NextRx gains and other items, adjusted income fell 21 percent to $536 million, or $1.16 per share. Analysts on average expected $1.02 per share, according to Thomson Reuters I/B/E/S.

Operating revenue fell 2 percent to $15.06 billion. Analysts expected $15.13 billion.

Enrollment stood at 33.7 million at the end of December, down 3.9 percent from a year earlier, as the rise in unemployment reduced its customers in employer-based plans.

But membership in WellPoint's more lucrative commercial plans, for which it assumes full insurance risk, was about 100,000 members higher than expected.

The Indianapolis-based company spent 84.8 percent of its premium revenue on medical expenses, higher than 83.4 percent a year ago, on costs from the flu and Cobra coverage for people who lose their jobs. But the medical cost ratio fell in its businesses serving the elderly and low-income Americans, WellPoint said.

WellPoint projected 2010 earnings of at least $6.00 per share, compared with analyst expectations of $6.11. On that basis, the company posted 2009 earnings of $6.09 per share.

The company said earlier this month it expected modest growth in 2010 adjusted profit, reflecting lower operating earnings offset by expected share buybacks.

(Reporting by Lewis Krauskopf; Editing by Lisa Von Ahn and Derek Caney)