[Formula Presented] symmetry breaking in supersymmetric [Formula Presented] models

We study the electroweak and (Formula presented) symmetry breaking patterns in models with the particle content of supersymmetric (Formula presented) including standard model singlets (Formula presented) and exotic quarks (Formula presented) Motivated by free fermionic string models, we do not require (Formula presented)-type relations between Yukawa couplings. In particular, we assume that baryon and lepton numbers are conserved, so that the exotic quarks can be light. Gauge invariance allows Yukawa interactions between (Formula presented) and Higgs doublets, and between (Formula presented) and the exotic quarks, allowing radiative (Formula presented) symmetry breaking and the generation of an effective (Formula presented) parameter at the electroweak scale. For both the (Formula presented) and (Formula presented) models, universal soft supersymmetry breaking parameters and Yukawa universality at the high (string) scale do not yield acceptable low energy phenomenology. Relaxing universality, we find solutions with phenomenologically acceptable values of (Formula presented) and the (Formula presented) mixing angle. In addition, by varying the (Formula presented) charge assignments due to the mixing of (Formula presented) and (Formula presented) of (Formula presented) it is possible to have acceptable low energy phenomenology with universal boundary conditions.