  We consider systems of Dp branes in the presence of a nonzero B field. We
study the corresponding supergravity solutions in the limit where the branes
worldvolume theories decouple from gravity. These provide dual descriptions of
large N noncommutative field theories. We analyse the phase structure of the
theories and the validity of the different description. We provide evidence
that in the presence of a nonzero B field the worldvolume theory of D6 branes
decouples from gravity. We analyse the systems of M5 branes and NS5 branes in
the presence of a nonzero C field and nonzero RR fields, respectively. Finally,
we study the Wilson loops (surfaces) using the dual descriptions.
