The search for charged Higgs bosons, which are predicted in supersymme
tric theories, is difficult at hadron colliders if the mass is large.
In this paper we present the theoretical set-up for the production of
charged Higgs-boson pairs at the LHC in gluon-gluon collisions: pp -->
gg --> H+H-. When established experimentally, the trilinear couplings
between charged and neutral CP-even Higgs bosons, H(+)H(-)h(0) and (H
+H-H0), can be measured. (C) 1998 Elsevier Science B.V.