The singer-songwriter revealed that she was happy to be working with Keisha Buchanan, Mutya Buena and Siobhan Donaghy because she "loved their sound".
Sandé told MTV News: "I've written for the original lineup of the Sugababes, which I'm very happy about because I just loved them when they first came out.
"I loved their sound, it was so cool. It was very different, so I'm happy to kind of be involved in what started the whole Sugababes journey. It sounds amazing."
The original lineup have yet to officially confirm their reunion, but it has been reported that they will have to come up with a new name as they no longer own the rights to use Sugababes.
MNEK, Asterix, Craze & Hoax, Tanika, Mojam and Naughty Boy are all rumoured to have contributed to the girl group's new album.
> Professor Green not working with original Sugababes - video
Watch the original lineup of the Sugababes perform 'Overload' below: