As of SAP CRM 5.2, PI 2005.1 and higher, the standard SAP system technically supports the data exchange for a Multiple CRM scenario. In this technical scenario the SAP ERP system is connected to more than one SAP CRM system.
Yes and we are doing it in our current scenario with CRM 5.0 and CRM 7.0 being connected to one ECC 6.0. Not sure with CRM 4.0. You can refer OSS Note 1143540 for more details which talks about MCRM scenario.
The CRM systems are independent. No master data or transactional data will be transferred directly between the CRM systems. This functionality can be implemented using the XIF adapter on project basis.
If sales offices/groups are shared across multiple CRM systems a special handling for ID generation for multiple used organisational units is necessary. These has to be configured manually.
Mobile Sales clients are synchronized only to the u201Ahomeu2018 CRM system.
If the data exchange of sales documents has been implemented on project basis, a sales document may only be changed on one system. A cross system lock (CSL) mechanism has to be implemented.
Hope this helps