Algebraic structure in 0 < c <= 1 open-closed string field theories

We apply stochastic quantization method to Kostov's matrix-vector models fo r the second quantization of orientable strings with Chan-Paton like factor s, including both open and closed strings. The Fokker-Planck hamiltonian de duces an orientable open-closed string field theory at the double scaling l imit. There appears an algebraic structure in the continuum F-P hamiltonian including a Virasoro algebra and a SU(r) current algebra. (C) 1999 Publish ed by Elsevier Science B.V. All rights reserved.