Shares in Twitter have dropped 7% after Salesforce chief executive Marc Benioff said his firm would not bid for the social media website.
Mr Benioff told the Financial Times his firm had “walked away” from any potential deal.
Google, Apple and Walt Disney also reportedly considered – and then rejected – bidding.
Cloud software company Salesforce had been thought to be the most likely buyer of the business.
Twitter’s shares fell about 7% to $16.60, while those of Salesforce rose more than 6% to about $74.
Last month, Twitter’s shares soared by 20% after a report said it had received takeover approaches, and that its directors were open to a deal, which could come by the end of the year.
Twitter had been the subject of takeover rumours prior to that, but was getting closer to a sale, US business news channel CNBC reported.