Twitter shares have surged by a fifth after reports that it was the target of a possible takeover.
Google and cloud computing company Salesforce were among those in talks with the social media company, according to US broadcaster CNBC.
The report said Twitter could receive a formal bid by the end of the year.
It comes as the business grapples with its slowest revenue growth since going public three years ago and a sluggish rise in users.
Reuters quoted sources confirming that the company had started talks with several technology companies to explore a sale.
Shares climbed as much as 21%, giving the company a market value of close to $16bn (£12bn).
It was the biggest rise since Twitter’s stock market launch in 2013.
There was no immediate comment from any of the companies.
Twitter has been the focus of much takeover speculation amid disappointing results.
In its latest earnings statement, for the second quarter, revenues rose 20% to $602m (£464m) but fell short of Wall Street estimates.
It added three million users, just 1% up on the first quarter.
Twitter’s co-founder, Jack Dorsey, returned to the company as chief executive last year.
It faces a battle for users and advertisers with rivals such as Instagram and Snapchat.
(c) Sky News 2016