Lakshmipur Additional Session Judge Md Saidur Rahman Gazi gave the verdict on Tuesday afternoon.
The convicted criminals are Alam, Miraz, Monju, Mohi Uddin, Kalam Munshi, Mamun alias Saiful Islam Mamun, Bhutto alias Abdus Shaheed, Moin Uddin, Morshed Alam, Masud and Abdul Bashar.
The court also acquitted four others from the charge.
Lakshmipur Judge Court Assistant Public Prosecutor (APP) Abul Kalam confirmed the matter to the Dhaka Tribune.
Babar was shot and hacked to death by the convicts at Tarakandi village on March 8, 2003.