Mutya Buena, Siobhan Donaghy and Keisha Buchanan are in the studio together for the first time since 2001 and Emeli Sande - who is writing tracks for them - is sure they will do well when they eventually release a single.
Emeli told The Sun newspaper: ''What we've done so far sounds great.
''They're going to make people stand up and notice.''
Keisha , Siobhan and Mutya formed the girl group together in 1998, but left one-by-one and were replaced, until by September 2009, no original members remained.
They are now said to be managed by Felix Howard, who wrote their debut single 'Overload' and the track 'Stronger'.
The new group have not decided on a name and do not have a record deal, but are said to be in talks with a number of different labels.
Meanwhile, Sugababes - now made up of Heidi Range, Amelle Berrabah and Jade Ewen - continue with their career, but are currently on hiatus.