how to replace a part of a string with a newline??

Hi

Ive got this string :

Importer__OPT__Trading Company__OPT__Service Provider

How do i make it equivalent to
- Importer
- Trading Company
- Service Provider


Ive tried using translate function, but it replaces all instances of the 
letters O,P,T as well.I did something like:
translate(text(),'__OPT__',':')

It gives the following output is Importer:rading Company:Service rovider 
which i dont want.
Any easy way to do it??

Thanks in advance
Regards
Varun