UnitedHealth Group's net income surged 16% in the fourth quarter, but shares slipped in early trading after it also reported revenue that missed analyst expectations.

The nation's largest insurer said Wednesday that its top line grew 4% to $60.9 billion in the final quarter of 2019.

Analysts were expecting, on average, about $60.96 billion, in revenue according to FactSet.

The insurer, a component of the Dow Jones Industrial Average, normally tops Wall Street expectations for both earnings and revenue every quarter.

UnitedHealth brought in more than $47 billion in insurance premiums during the quarter, but its product sales tumbled 11% to $7.62 billion.

Product sales include the company's pharmacy benefit management operation, which took a hit when it lost business from Cigna after the rival insurer bought its own PBM.

Overall, UnitedHealth earned $3.54 billion in the final quarter of 2019, with adjusted results of $3.90 per share.

That beat Wall Street forecasts. Analysts expected $3.78 per share, according to FactSet.

The Minnetonka, Minnesota, company covers more than 49 million people, including 5.7 million in its international business. Health insurance is UnitedHealth's biggest business.

But most of its operating earnings in the fourth quarter came from its Optum segment, which runs a growing number of clinics and urgent care and surgery centers as well as the PBM business.

Optum pulled in $3 billion in operating earnings, compared to $2.1 billion from the insurance side. Optum's operating margin topped 10%, which was more than twice as big as the insurance business.

UnitedHealth Group Inc. on Wednesday also reaffirmed profit expectations for 2020 that it first laid out at its investor conference last month. It expects adjusted earnings of between $16.25 and $16.55 per share in the new year.

Analysts expect per-share profits of $16.46 this year, according to FactSet.

Company shares slipped 46 cents to $287.50 in premarket trading Wednesday. The stock climbed 18% last year.