  Based on a measurement of high momentum eta' production in B decays, we
determine the charmless inclusive B -> eta'X_(nc) branching fraction in the
lab-frame momentum interval 2.0<P_eta'<2.7 GeV/c. Using 9.7x10^6 BBbar pairs
collected at the Upsilon(4S) center-of-mass energy with the CLEO II and II.V
detector configurations, we find Br(B -> eta'X_(nc)) = (4.6 +- 1.1 +- 0.4 +-
0.5)x 10^(-4) in the 2.0<P_(eta')<2.7 GeV/c momentum range, where the
uncertainties are statistical, systematic, and from subtraction of background
from B decays to charm, respectively.
