Do you submit your work to Getty images? If so can you use your submitted pictures for anything else or do they own them?
STAY AWAY FROM GETTY. They do not give the photographers the fair share of the profit (like 30/70) If you are going the stock agency route I would go with someone who is going to give you your fair share (50/50)
As for other stock agencies, generally they do not want you to upload the same or similar images to others agencies but you still own all the rights to your photos.