delete three columns of two grouped columns according to common value of two column

I have 2 sets of three grouped columns in one worksheet. This stretches for 30000 rows. Sample data is below:

1	11	100	1	11	1000
2	12	200	2	200	2000
3	13	300	3	13	3000
4	14	400	4	400	4000

i want a macro Do like this code :
Code:
when (old seial)=(new serial) then delete (new code) AND (new serial) AND(new amount)
table after algorithm is below :

1	11	100	4	400	4000
2	12	200	2	200	2000
3	13	300
4	14	400