Now I have a method A on this session bean, wich has to call a method B.
But this method B should be executed outside of A's transaction
Why? If method B is part of the business logic for Method A then I can't think why you would want the transaction in B to succede if the method A fails?
You can't do what you want without two seperate
EJB calls, otherwise if method A requires a new transaction, and it calls method B, then method B will always use the same transaction as method A.