I saw this reported in today's Sun Online.
I think it's good that Darius has signed to a different label from Will and Gareth - it will give him some space to develop his own style of music. I seem to remember from his Pop Idol final interview that he was looking to be working with Nicki Chapman in the future, so that could well mean that 19 will be handling the management side of his career.
Feefs - there's not much info on the Mercury Records website, but a few artists who are signed to the label appear to be Dire Straits, the Beautiful South, Elton John, Marti Pellow and Texas. Quite a diverse range of artists there.
Good luck to Darius - looking forward to his first release.