Its simple to say that if you have three or more business pages it will take lot of time to update or share some thing in your post. That is why we would always likes to set Managers to our own Business Page. This is you can just give the authority but not ownership.
Steps to Follow:
1. Go to your Google+ Business Page(Example: https://plus.google.com/u/0/b/101094135981777692560/)
2. Click on Google+ Account and click Managers in the Drop Down.
You can see the owner profile and managers list(if you have already added manager)
3. Enter the Email address of Manager that you would like to invite and click Invite Button.
NOTE: Manager is different from OWNER so don’t click TRANSFER Owner unless you are sure to do it.