  Charm penguin diagrams are known to be the main contribution to charmless B
decay process with strangeness variation equal to minus one, which is the case
of $B^\pm \to K^\pm K^+ K^-$ decay. The large phase space available in this and
other B three-body decays allows non trivial final state interactions with all
sort of rescattering processes and also access high momentum transfers in the
central region of the Dalitz plane. In this work we investigate the charm
Penguin contribution to $B^\pm \to K^\pm K^+ K^-$, described by a hadronic
triangle loop in nonperturbative regions of the phase space, and by a partonic
loop at the quasi perturbative region. These nonresonant amplitudes should have
a particular structure in the Dalitz plane and their contributions to the final
decay amplitude can be confirmed by a data amplitude analysis in this channel.
In particular, the hadronic amplitude has a changing sign in the phase at
$D\bar{D}$ threshold which can result in a change of sign for the CP asymmetry.
