UME configuration using two Databases

Hi Experts,

We have a scenario where we are using two data sources for maintaining our Users(SAP Portal 7.0).

1)User base A uses Portal DB

2)User base B uses ABAP as User repository.

Is there any way to configure the Portal UME to use the above 2 different datasources?

Or can any one please suggest the best possible option to optimize the use of data sources and work smartly.

Early response is highly appreciated.

Thanks in advance,

Prabha