N=3 and N=4 Two-Form Supergravities

We construct the Lagrangeans of N=3 and N=4 two-form supergravities. The two-form gravity theories are classically equivalent to the Einstein gravity theories and can be formulated as gauge theories. The gauge algebras used here can be identified with the subalgebra of N=3 superconformal algebra and SU(2)\times SU(2)\times U(1)-extended N=4 superconformal algebra.