Incerting 3 new records for each entry

Hi Experts,
 
I have this situation where i seek for your assistance-
 
I have a table-
 
MATNR   MTART   WERKS   NAME
001         A          AA         NEW
002         B          AC         NEW1
003         B          AD         NEW2
004         A          AE          NEW3
 
Now when ever i find a MTART= B i have to insert 2 more records for the same MATNR  the two more records are same i.e-
 
MTART= B,WERKS= ZZ,NAME=OLD1
MTART=B,WERKS=YY,NAME=OLD2
 
with addition to the MATNR, so the output sould look like-
 
MATNR   MTART   WERKS   NAME
001         A          AA         NEW
002         B          AC         NEW1
002         B          ZZ         OLD1
002         B          YY         OLD2
003         B          AD         NEW2
003         B          ZZ         OLD1
003         B          YY         OLD2
004         A          AE          NEW3
 
 
Please let me know how to implement this logic.
 
Thanks
Ashique