Oman Employment Visa Application
You can apply for an Oman employment visa without canceling your existing Bahrain visa. There is an exception: a medical report from the authorized medical center (GAMCA) may not be required if you already have a Bahrain visa. However, when you undergo the Oman MOH medical, you will need to obtain a medical report from any authorized medical center in Oman.
Previously, it was common practice for employers to provide an undertaking at the time of applying for a visa for individuals with GCC visas, stating that the visa would be canceled later. This practice is no longer being followed. In your case, there shouldn't be any issue as your Bahrain visa is also expiring in 2013.
All the best,
Regards,
Gurumoorthy T