  Continuing work initiated in an earlier publication [Ichita, Yamada and
Asada, Phys. Rev. D 83, 084026 (2011)], we reexamine the post-Newtonian effects
on Lagrange's equilateral triangular solution for the three-body problem. For
three finite masses, it is found that a triangular configuration satisfies the
post-Newtonian equation of motion in general relativity, if and only if it has
the relativistic corrections to each side length. This post-Newtonian
configuration for three finite masses is not always equilateral and it recovers
previous results for the restricted three-body problem when one mass goes to
zero. For the same masses and angular velocity, the post-Newtonian triangular
configuration is always smaller than the Newtonian one.
