The announcement came on the third day of peace talks, brokered by the Norwegian government and taking place amid tight security in Thailand.
The government delegation says it marks a significant step forward that both sides have agreed to look at the fundamental political issues underlying the conflict.
The Sri Lankan government's chief negotiator, G L Peiris, said the new committee would consist of two members from each side of the conflict and would be headed by himself and chief Tamil Tiger negotiator, Anton Balasingham.
