  We study the effect of varying strength, $\delta$, of bond randomness on the
phase transition of the three-dimensional Potts model for large $q$. The
cooperative behavior of the system is determined by large correlated domains in
which the spins points into the same direction. These domains have a finite
extent in the disordered phase. In the ordered phase there is a percolating
cluster of correlated spins. For a sufficiently large disorder
$\delta>\delta_t$ this percolating cluster coexists with a percolating cluster
of non-correlated spins. Such a co-existence is only possible in more than two
dimensions. We argue and check numerically that $\delta_t$ is the tricritical
disorder, which separates the first- and second-order transition regimes. The
tricritical exponents are estimated as $\beta_t/\nu_t=0.10(2)$ and
$\nu_t=0.67(4)$. We claim these exponents are $q$ independent, for sufficiently
large $q$. In the second-order transition regime the critical exponents
$\beta_t/\nu_t=0.60(2)$ and $\nu_t=0.73(1)$ are independent of the strength of
disorder.
