Dont think so. I would luv to know where it is written if there is.
I have Australian ATPL, US ATP, NZATPL, JAMIACA ATPL. I have also had validations to fly in Mexico , Panama and Jamiaca off my USATP.
All these are ICAO licences, and are either aquired by revalidation or through written and flight tests. They may or may not be valid unless the original Licence is current (medical aswell) on which the secondary licence was granted.
Never heard of a limit to it. I think there are drivers out there with more than me aswell.
Regards
Sheep