Abstract
A string in four dimensions is constructed by supplementing it with forty four Majorana fermions. The central charge is 26. The fermions are grouped in such a way that the resulting action is supersymmetric. The super-Virasoro algebra is constructed and closed by the use of Jacobi identity. The tachyonic ground state decouples from the physical states. GSO projections are necessary for proving modular invariance and space-time supersymmetry is shown to exist for modes of zero mass. The symmetry group of the model desends to the low energy group SU(3)x SU(2)x U(1)x U(1).