Resonating group kernels for the nine-quark NNN system are used to show that the quark structure of nucleons leads to nonlocal three-body forces which are short ranged and attractive. They give a net contribution of 0.2 MeV to the three-nucleon binding energy, 0.9 MeV via quark-quark interaction terms whose effect is partially canceled by kinetic energy contributions to the exchange kernels.