Multi-site or group certifications are possible for management systems, although they are not common across continents. The real determination is the applicability of the QMS rules and polices across the different locations, if this is too different then a multi-site certification can be difficult. The certification comes down to the scope identified for the QMS, and this scope can include one location or several, but as stated if the multiple locations are very different from each other in processes, products or services this can be difficult. Additionally, legal requirements may be different across locations on different continents.
It is also important to note that not all certification bodies will be willing to do a certification like this. To certify multiple locations, you will need all locations audited and this may not be possible or accepted for all certification bodies.