Customer Accounts - merge/transfer functionality?

Summary:

Is there any possibility of transferring Customer Accounts and Sites from one Party to Another?

Content (required):

In case we have:

Party A with Customer Accounts a, b, c and Sites a1,b 2, c3

Party B with Customer accounts x, y, z and Sites x1, y2, z3

Can we move Customer Account c + site c3 into Party B while keeping Party A active with Accounts a and b and Sites a1 and b2?

After change:

Party A with Customer Accounts a, b and Sites a1, b2

Party B with Customer accounts x, y, z, c and Sites x1, y2, z3, c3