Mixing GPL and BSD-style licenced code

Dear all,

I would very much appreciate some advice.  I would like to make use of a 
database storage manager distributed under a BSD-style licence, however 
I anticipate that it will require extensive modification.  I would like 
these modifications to be distributed under the GPL.  If I included a 
statement like the one below in the modified files, would the GPL 
"stick" to the modified code?

"Modified portions of this software are distributed under the the terms 
of the GPL.  The original source code is distributed under the following 
licence:
<insert BSD licence>"

Any help or opinions much appreciated.

Cheers,
John