Coupled Channel Calculation of Bound-Free Electron-Positron Pair Producti on in Collisions of Highly Charged Heavy Ions M. Gail$^{A,B}$, N. Toshima$^A$, N. Gr\"un$^B$ and W. Scheid$^B$ $^A$ Institute of Applied Physics,University of Tsukuba, Tsukuba, Ibaraki 305-8573 \\ $^B$ Institut f\"ur Theoretische Physik II, Justus-Liebig-Universit\"at, 35392 Giessen, Germany We investigate bound electron-positron pair creation within a coupled channel formalism using a very large basis set composed of Coulomb-Dirac wave functions. We compare our results with perturbation theory and with values obtained from an analytic soution in the ultrarelativistic limit.