Greater Multiweapon Fighting( Deities and Demigods, p. 50)
A deity with three or more hands can fight with a weapon in each hand. The deity can make up to three attacks per round with each extra weapon.
The deity may make up to three extra attacks with each weapon it wields, albeit with a -5 penalty on the second attack with each weapon and a -10 penalty on the third.
This feat replaces the Greater Two-Weapon Fighting feat for deities with more than two arms.