Measurement of B→Ds(*)Kπ branching fractions

We report a measurement of the exclusive B+ meson decay to the D-s(()K-)(+)pi(+) final state using 657 x 10(6) B (B) over bar pairs collected at the gamma(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We use D-s -> D-s(-) -> phi pi(-), (K) over bar*(892)K-0(-) and (KSK-)-K-0 decay modes for D-s(()()) reconstruction and measure the following branching fractions: B(B+ -> Ds-K+pi(+)) = (1.71(-0.07)(+0.08)(stat)(-0.20)(+0.20)(syst) +/- 0.15(B-int)) x 10(-4) and B(B+ -> D-sK--(+)pi(+)) = (1.31(-0.12)(+0.13)(stat)(-0.25)(+0.25)(syst) +/- 0.12(B-int)) x 10(-4). The uncertainties are due to statistics, experimental systematic errors, and uncertainties of intermediate branching fractions, respectively.