SAN FRANCISCO -- LinkedIn shares plunged as much as than 28 per cent in after-hours trading Thursday after it reported better-than-expected results for the fourth quarter but provided a weak forecast for 2016.

The professional networking service's adjusted earnings and revenue beat Wall Street's estimates for the last three months of 2015, thanks to strong demand for its hiring and recruiting software. But it issued a forecast that was far below what analysts were expecting.

Among other things, LinkedIn said it will phase out a new advertising service that hasn't worked out as planned, which will cause it to forego roughly $50 million in near-term revenue.

Mountain View, California-based LinkedIn Corp. reported a loss of $8.4 million, compared with a $3 million profit a year earlier. That amounted to a loss of 6 cents a share in the latest quarter, but the company said it earned 94 cents a share after adjusting for stock compensation and other one-time items. Analysts surveyed by FactSet were expecting adjusted earnings of 78 cents a share on revenue of $857 million.

Fourth-quarter revenue rose 34 per cent to $862 million.

Despite the strong finish, the company disappointed investors by forecasting adjusted earnings for the current period will be 55 cents a share on revenue of roughly $820 million. Analysts were expecting first-quarter adjusted earnings of 75 cents a share on sales of $868 million.

The company's forecast for the full year was also lower than expected. LinkedIn said growth in its all-important "Talent Solutions" segment, which provides software tools for employers and recruiters, will slow from 30 per cent last year to mid-20 per cent in 2016. It blamed an economic downturn in Europe and Asia.

The online company also said a new advertising program called "Lead Accelerator" would be discontinued because it "required more resources than anticipated."

LinkedIn is often described as a social-networking service like Facebook or Twitter, which make money primarily from digital ads. But LinkedIn has a different business model: It gets nearly two-thirds of its revenue from fees that employers and recruiters pay to use its platform, while advertising and premium subscriptions contribute the rest.

The company has seen steady revenue growth over the last five years, but it often reports a net loss because of big stock grants that it awards to employees.

Shares of LinkedIn have been on a roller-coaster over the last year. The stock plunged last spring when the company lowered its revenue forecast and warned of short-term costs associated with its $1.5 billion purchase of online education company Shares surged again in the fall, but dropped more than 20 per cent again in the last three months.

LinkedIn has said it expects to continue growing as it expands in China and other markets. It's also counting on more revenue from online training courses and software that commercial sales representatives can use to drum up business from their LinkedIn contacts.

But analysts warn LinkedIn could face more competition from companies like GlassDoor, which shows job postings and workers' ratings of companies, or Facebook, which recently launched a service for workers to communicate with their colleagues.