Issue is with LIBPATH ..In Your Datastage director check in Environment variables setting what is the value assiged to LIBPATH of Teradata.
For example like below:
Include LIBPATH before executing bteq script and after the end of bteq script
LIBPATH=/opt/teradata/client/13.0/tbuild/lib64; export LIBPATH
The best way to solve this issue call the library just before invoking the bteq
it should work!