CRM_MKTBP_CHANGE_BP not working

Hello friends,

We are using the FM CRM_MKTBP_CHANGE_BP to update the marketing attributes.

But this is removing the maintained values for that set and updating the new values. But we are expecting it should add the new values to the BP.

Please find the code

**  Maintain marketing for business partner.
     CALL FUNCTION 'CRM_MKTBP_CHANGE_BP'
       EXPORTING
         iv_profile_template_id = ls_mkt-attr_set
         iv_bp_guid             = ls_mkt-partner_guid
         iv_fcode               = 'C'
         iv_commit              = lv_commit
       TABLES
         it_imp_seltab          = ls_mkt-imp_seltab
         et_return              = lt_return.

Kindly suggest whether it is a standard behaviour or something else need to be passed.

Let me know if you need more details.

Thanks,

Ravi Teja