Abstract. The four-body equations of Alt, Grassberger and Sandhas, in the form that the (2) + (2) subsystem amplitudes are treated by the convolution method, are solved for separable two-body interactions between nucleon pairs in the channels 3S1-3D 1 (too alone) and 1S 0. All L = 0 and L = 1 (3) + 1 subamplitudes are represented in a separable form using the energy dependent pole expansion. The contribution of p-wave (3)+ 1 subamplitudes to the 4He binding energy, threshold scattering observables and low energy cross sections for n3H ~ n3H, p3He ~ p3He, dd -+ dd and dd -+ pall reactions is studied for different two-body potentials.