SAN FRANCISCO — Netflix’s fourth-quarter earnings soared sixfold as the Internet video service added another 2.3 million U.S. subscribers to burnish its status as one of the world’s most popular entertainment outlets.

The financial results announced Wednesday topped analyst estimates, and Netflix basked in Wall Street’s adulation. The company’s stock surged $58.57, or more than 17 percent, to $392.30 in extended trading.

If the shares behave similarly in Thursday’s regular session, the stock will hit its highest level since Netflix Inc. went public nearly 12 years ago.

Investors tend to focus more on Netflix’s subscriber growth because the widening audience provides the company with the means to negotiate the rights to show even more compelling content to show in the future.

“Internet video is catching hold,” Netflix CEO Reed Hastings said in a Wednesday interview with The Associated Press. “Consumers love that they can watch what they want when they want it. There is just a lot of consumer appetite for this.”

Netflix ended December with 33.4 million U.S. subscribers who stream video over high-speed Internet connections, up from 31.1 million in September. The company picked up another 1.74 million subscribers outside the U.S. to end last year with 10.9 million international customers.

People are still flocking to the service. Netflix expects to gain an additional 2.25 million U.S. subscribers during the first three months of this year.

The strong showing follows a year in which Netflix’s stock nearly quadrupled in a resounding comeback from a steep downturn triggered during the summer of 2011 after the Los Gatos, Calif., company split apart its Internet video service and DVD-by-mail service. The division resulted in price increases of as much as 60 percent for customers who wanted to keep both options.

Hastings apologized and the uproar eventually died down as the company began stockpiling its $8-per-month streaming service with more original programming, such as the Emmy-award winning “House of Cards.” The second season of that series will be released Feb. 14, contributing to management’s optimism about its subscriber growth for the current quarter ending in March.