Index: c/blacs.c
===================================================================
--- c/blacs.c	(revision 6589)
+++ c/blacs.c	(working copy)
@@ -543,29 +543,19 @@
   PyArrayObject* b; // destination matrix
   PyArrayObject* desca; // source descriptor
   PyArrayObject* descb; // destination descriptor
-  PyObject* comm_obj = Py_None; // intermediate communicator, must
-                                // encompass adesc + bdesc
-  char order='R';
+
   char uplo;
   char diag='N'; // copy the diagonal
-  int nprocs;
-  int iam;
   int c_ConTxt;
   int isreal;
   int m;
   int n;
   int one = 1;
 
-  if (!PyArg_ParseTuple(args, "OOOOOiiic", &desca, &descb, &a, &b,
-                        &comm_obj, &m, &n, &isreal, &uplo))
+  if (!PyArg_ParseTuple(args, "OOOOiiiic", &desca, &descb, &a, &b,
+                        &c_ConTxt, &m, &n, &isreal, &uplo))
     return NULL;
 
-  // Create intermediate blacs grid on this communicator
-  MPI_Comm comm = ((MPIObject*)comm_obj)->comm;
-  Cblacs_pinfo_(&iam, &nprocs);
-  MPI_Comm_size(comm, &nprocs);
-  c_ConTxt = Csys2blacs_handle(comm);
-  Cblacs_gridinit(&c_ConTxt, &order, 1, nprocs);
   if (uplo == 'G') // General matrix
     {
       if(isreal)
@@ -585,7 +575,6 @@
 		   (void*)COMPLEXP(b), one, one, INTP(descb), c_ConTxt);      
     }
     
-  Cblacs_gridexit(c_ConTxt);
   Py_RETURN_NONE;
 }
 
Index: gpaw/blacs.py
===================================================================
--- gpaw/blacs.py	(revision 6589)
+++ gpaw/blacs.py	(working copy)
@@ -431,6 +431,7 @@
         triangular and L for lower triangular. The latter two are useful
         for symmetric matrices."""
         self.supercomm = supercomm
+        self.supercomm_bg = BlacsGrid(self.supercomm, self.supercomm.size, 1)
         self.srcdescriptor = srcdescriptor
         self.dstdescriptor = dstdescriptor
         assert uplo in ['G', 'U', 'L'] 
@@ -467,7 +468,7 @@
         _gpaw.scalapack_redist(srcdescriptor.asarray(), 
                                dstdescriptor.asarray(),
                                src_mn, dst_mn,
-                               self.supercomm.get_c_object(),
+                               self.supercomm_bg.context,
                                subN, subM, isreal, uplo)
     
     def redistribute(self, src_mn, dst_mn):