Investors hammered Twitter Inc (TWTR.N) on Thursday after the social network reported its slowest quarterly revenue growth since going public in 2013, struggling to attract advertisers amid intense competition from Snap Inc's Snapchat and Facebook Inc (FB.O).

The company's shares fell as much as 10 per cent to US$16.81 in premarket trading.

Revenue grew just 1 per cent to US$717.2 million, missing analysts' average estimate of US$740.1 million, according to Thomson Reuters I/B/E/S.

Revenue from advertising declined year-over-year to US$638 million, and the company warned that ad revenue growth would continue to lag audience growth during 2017.

"Advertising revenue growth may be further impacted by escalating competition for digital ad spending and Twitter's re-evaluation of its revenue product feature portfolio, which could result in the de-emphasis of certain product features," the company said.

The results show advertisers are shifting dollars to Facebook, said Michael Pachter, a Wedbush Securities analyst. Facebook said last week its revenue soared US$3 billion from a year earlier.

"There isn't a growth story here," Pachter said of Twitter.

"I don't think they can grow revenue without showing user growth," he said. "They have to convince advertisers that they will reach an expanding audience, or they will have trouble competing for new revenue dollars."

Twitter's net loss widened to US$167.1 million, or 23 cents per share, in the fourth quarter ended Dec. 31, from US$90.24 million, or 13 cents per share, a year earlier.

The company's adjusted profit, however, beat sharply lowered estimates.

"While revenue growth continues to lag audience growth, we are applying the same focused approach that drove audience growth to our revenue product portfolio," Chief Executive Jack Dorsey said in a statement. "This will take time, but we're moving fast to show results."

Excluding items, the company earned 16 cents per share in the fourth quarter, beating the average estimate of 12 cents per share.

San Francisco-based Twitter was abuzz with takeover chatter last year involving big names such as Salesforce.com Inc (CRM.N) and Walt Disney Co (DIS.N). That speculation dissipated amid a lack of concrete offers.

Twitter was also hit by a string of executive departures in 2016, including in its products team, which had three heads in less than a year.

Dorsey was upbeat about audience trends, saying in his statement the company saw "strong growth continuing" in future daily active usage.

The user base increased 4 per cent in the fourth quarter to 319 million average monthly active users, Twitter said.

Analysts on average had expected 319.6 million monthly active users, according to market research firm FactSet StreetAccount.

Twitter's user growth benefited from social media frenzy relating to the U.S. presidential election as well as the growing follower base of President Donald Trump, who has 24.3 listed followers on the network.

Trump has been using Twitter to air his views, bypassing traditional media outlets.

"The shocking part is that the Trump effect was zero. Their growth actually slowed during the quarter," Pachter said.

Twitter has upgraded its offerings with several new features, including live video broadcasts from its app.

"While none of them will likely materially change Twitter's user/usage growth, these product innovations are a positive step," RBC Capital Markets analysts wrote in a pre-earnings note.

Restructuring charges in the latest quarter ballooned to US$101.2 million from US$12.9 million a year earlier.

Twitter said in October it would cut 9 per cent of its global workforce as part of a broader restructuring.