The panabas, also known as nawi, is a large, curved sword used by certain ethnic groups in the southern Philippines. The panabas is one of many bladed weapons portrayed in the "Weapons of Moroland" plaque that has become a common souvenir item and pop culture icon in the Philippines.
This blade was made by a Maguindanaon blacksmith - Norsadie A. Abdulradzak from Shariff Aguak, Maguindanao Del Sur and has told me that this is one of their native weapons.