Users could enjoy as many as 47 additional characters for their tweets following the change, with images currently taking up 24 characters, while links are often shortened to 23.
Sources told Bloomberg the new format could be introduced as early as two weeks’ time, but the micro-blogging site has yet to comment.
The website has reportedly been exploring ways to allow people to post longer messages, while maintaining its commitment to bite-size output.
CEO Jack Dorsey wrote in January: “We’ve spent a lot of time observing what people are doing on Twitter, and we see them taking screenshots of text and tweeting it.
“Instead, what if that text...was actually text? Text that could be searched. Text that could be highlighted. That’s more utility and power.”
But Mr Dorsey also added in an interview in March that there were no plans to scrap the upper ceiling on the character count altogether.
Twitter first introduced its character limit shortly after its launch in 2006 to complement SMS messages, which were formerly capped at 160 characters.