On your PROD database, isue:

SELECT * FROM global_name;

I belive you'll get the following answer: ''PROD.ABC.COM".

So you have the folowing options:

1. Name your database link PROD.ABC.COM (Note: this should be the *name* of your database link, your connect string in "CREATE DATABASE LINK PROD.ABC.COM ... USING 'PROD.WORLD'; can remain uncahnged)
2. Set GLOBAL_NAMES=FALSE on your PROD database.
3. Change the global name of your PROD database to PROD.WORLD by using "ALTER DATABASE RENAME GLOBAL_NAME ..."