  We present a measurement of the branching fraction and time-dependent CP
violation parameters for B0 -> D*+ D*- Ks decays. We also obtain an upper limit
on the product branching fraction for the possible two-body decay, B0 ->
Ds1+(2536) D*-. These results are obtained from a 414 fb-1 data sample that
contains 449e10^6 BBbar pairs collected at the Upsilon(4S) resonance with the
Belle detector at the KEKB asymmetric e+e- collider.
