Motivated by a desire to attempt a unified description of some recently observed phenomena such as the unusual events in the deep underground experiments at Kolar, the dilepton events initlated by high energy laboratory neutrino beams, the possible production of a new heavy lepton ine+e− annihilation along with the conventional weak interaction processes, a U3 gauge theory of weak and electromagnetic interactions is proposed. The theory makes use of six flavours of quarks (Charm, Taste and Grace plus the three old SU3 flavours), each in three colours, and correspondingly six lepton-types. The introduction of the corresponding fermions, and their assignment to representations of the proposed U3 group, is dictated by the stringent requirements of attaining an anomaly free renormalizable gauge theory and of ensuring that the neutral currents turn out strangeness-preserving. A spontaneous gauge symmetry breaking mechanism is employed to generate the mechanical masses of the vector gauge-bosons of the theory (other than the photon) and of the quarks and the leptons. Diagonalisation of the quark mass matrix so generated enables a natural introduction of mixing angles including the Cabibbo-angle.