Number of accounts to share a calendar with?

Hi,

We have some users who want to share their calendar with a couple of hundred of other users. For some reason, it seems they cannot share with more then more then 200 people.

I don't have any more detailled information at this moment yet, but could it be there's a limit in the number of users you can share your calendar with?

Thanks in advance.

with kind regards,

Tom