  We study the pure compact U(1) gauge theory with the extended Wilson action
(\beta, \gamma couplings) by finite size scaling techniques, in lattices
ranging from L=6 to L=24 in the region of \gamma <= 0 with toroidal and
spherical topologies. The phase transition presents a double peak structure
which survives in the thermodynamical limit in the torus. In the sphere the
evidence support the idea of a weaker, but still first order, phase transition.
For negative values of gamma the transition becomes weaker and larger lattices
are needed to find its asymptotic behaviour. Along the transient region the
behaviour is the typical one of a weak first order transition for both
topologies, with a region where 1/d < nu < 0.5, which becomes nu compatible
with 1/d when larger lattices are used.
