I am trying to change the environment setting "LC_CTYPE=en_GB.UTF-8" to
LC_CTYPE=en_US.UTF-8 but can't seem to find a way for this aside for using
the export command which is only valid for the acitve session (rebooting
losses the setting).

I tried setenv and Yast system sysconfig options but neither passes the
change to the env region.

How can I make the above change permanent?