Share price of Facebook fell more than 7% in after-hours trading (AHT) on Wednesday. The decline came amid warning that the social media giant's revenues could slow down in both the fourth quarter and in 2017.

Speaking at a conference call with investors on Wednesday, David Wehner, CFO at Facebook said, "We continue to expect that revenue growth rates will decline in Q4 as we lap a strong fourth quarter in 2015. We also continue to expect that our total Payments & Other Fees revenue in Q4 will be lower than it was in the fourth quarter of last year."

With regards to 2017, Wehner said that ad load, which refers to the number of advertisements the company can display in the news feed column for each user, could "come down meaningfully" after mid-2017.

He said that this ad load was one of the three primary factors fueling revenue growth in advertising. "With a much smaller contribution from this important factor going forward, we expect to see ad revenue growth rates come down meaningfully," he explained.

These comments is said to have worried investors as the language he used this time around was stronger than what he did last quarter.

The CFO of the world's largest social network also spoke about the company's plans to make additional investments in hiring engineers and expanding data centres.

"Adding top engineering talent remains one of our key investment priorities as we continue to execute on our 3-, 5- and 10-year roadmap. We will continue to invest in our ability to recruit top technology talent both in the Bay Area and beyond," he said.

"In addition, we expect to grow capital expenditures substantially as we continue to fund the ongoing data center expansion efforts that we have underway," Wehner was quoted as saying in the conference call statement.

This comment is said to have raised further concerns as additional expenditure would reduce margins next year, according to the Financial Times.

This decline in share price comes just hours after Facebook announced solid third quarter results. In another statement, Facebook said it had earned total revenues of $6.82bn(£5.53bn) for the three months to 30 September. This was up 59% year-on-year.

Also, its net income was up 166% on–year to $2.38bn for the period, while diluted earnings per share (EPS) came in 165% higher at $0.82. Commenting on the same, Facebook founder Mark Zuckerberg said, "We had another good quarter...We're making progress putting video first across our apps and executing our 10 year technology roadmap."