Search for rare quark-annihilation decays, B- --> D/s(*)- Phi

We report on searches for B{sup -} {yields} D{sub s}{sup -} {phi} and B{sup -} {yields} D*{sub s}{sup -} {phi}. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and {bar u} quarks in the B{sup -} meson. Our results are based on 234 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions {Beta}(B{sup -} {yields} D{sub s}{sup -}{phi}) < 1.9 x 10{sup -6} and {Beta}(B{sup -} {yields} D*{sub s}{sup -} {phi}) < 1.2 x 10{sup -5}. These results are consistent with Standard Model expectations.