In this article we present an example of a discrete group $\Sigma_\C\subset
PSL(3,\Bbb{R})$ whose action on $\P^2$ does no have invariant projective
subspaces, is not conjugated to complex hyperbolic group and its limit set in
the sense of Kulkarni on $\Bbb{P}^2_\Bbb{C}$ has infinite lines in general
position.
If $\Gamma$ is a discrete subgroup of $PSL(3,\Bbb{C})$, it is determined the
equicontinuity region $Eq(\Gamma)$ of the natural action of $\Gamma$ on
$\Bbb{P}^2_\Bbb{C}$. It is also proved that the action restricted to
$Eq(\Gamma)$ is discontinuous, and $Eq(\Gamma)$ agrees with the discontinuity
set in the sense of Kulkarni whenever the limit set of $\Gamma$ in the sense of
Kulkarni, $\Lambda(\Gamma)$, contains at least three lines in general position.
Under some additional hypothesis, it turns out to be the largest open set on
which $\Gamma$ acts discontinuously.
In this article we provide an algebraic characterization of those groups of
$PSL(3,\Bbb{C})$ whose limit set in the Kulkarni sense has, exactly, four lines
in general position. Also we show that, for this class of groups, the
equicontinuity set of the group is the largest open set where the group acts
discontinuously and agrees with the discontinuity set of the group.