The newly-promoted Barclays Premier League side desperately wanted to keep the 29-year-old midfielder but he has opted to move on.
"Having offered Zoltan the best contract the club could at this time, we could do no more," said manager Tony Mowbray.
Copyright (c) PA Sport 2008, All Rights Reserved.
Do YOU want to write for GiveMeSport? Get started today by signing-up and submitting an article HERE: http://gms.to/writeforgms