The founding members of the girl group - Keisha Buchanan, Mutya Buena and Siobhan Donaghy - are said to be working on new material before they make the reunion official.
According to Wot You Got the original trio "haven't signed anything official yet, but they have been demoing some new songs to see if they can re-capture that magic of their debut album".
The site added: "If they get that right, then they'll sign on the dotted lines."
Buchanan played her first solo gig earlier this year, showcasing some of her new material at an event in London.
However, no official release date or record deal has been announced for the star since she left the group back in September 2009.
Current member Jade Ewen recently revealed that it was "nice" to talk to Buchanan after filling her spot in the pop band two years ago.
Meanwhile, Buena recently won the rights to use the Sugababes name on Class 16 goods, which includes stationery, gift wrap and gift wrap ribbons.
Watch the original Sugababes perform their debut hit 'Overload' live below: