  In this paper, we prove a global bifurcation result for the existence of
non-radial branches of solutions to the paramterized family of
$\Gamma$-symmetric problems $-\Delta u=f(\alpha,z,u)$, $u|_{\partial D}=0$ on
the unit disc $D:=\{z\in \mathbb{C} : |z|<1\}$ with $u(z)\in \mathbb{R}^k$,
where $\mathbb{R}^k$ is an orthogonal $\Gamma$-representation, $f: \mathbb{R}
\times \overline{D} \times \mathbb{R}^k\to \mathbb{R}^k$ is a sub-linear
$\Gamma$-equivariant continuous function, differentiable with respect to $u$ at
zero and satisfying the conditions $f(\alpha, e^{i\theta}z,u)=f(\alpha, z,u)$
for all $\theta\in \mathbb{R}$ and $f(z,-u)=-f(z,u)$.
