NEW YORK (AFP) - A fake news report purportedly from Bloomberg about a possible US$31 billion (S$42 billion) takeover of Twitter spurred a 5 per cent surge in the social network's shares Tuesday before it was denied.

The report appeared on a "Bloomberg.market" web page virtually identical to the powerful financial news agency's real pages at "Bloomberg.com", and with links to other real Bloomberg reports.

The fake report said Twitter "is working closely with bankers after receiving an offer to be bought out for $31 billion," citing, as news agencies frequently do in such reports, "people with knowledge of the situation."

The report came out at about 11.35am and sent Twitter's shares jumping from US$36.90 to US$38.82 in minutes.

Fifteen minutes later, though, the shares fell back to near where they started.

"The story was fake and appeared on a bogus website that was not affiliated with Bloomberg," said Bloomberg spokesman Ty Trippet.

The agency itself reported that the website domain had been registered several days ago by someone in Panama.

Shares in Twitter were still up 3.3 per cent over Monday's close in early afternoon trade at US$36.96.

The shares though are sharply down from the year's peak of just over US$53 in April, with investors showing concern over the company's ability to build income on its hugely popular micro-messaging platform.