  The hierarchical scenario of structure formation describes how objects like
galaxies and galaxy clusters are formed by mergers of small objects. In this
scenario, mergers of galaxies can lead to the formation of massive black hole
(MBH) binary systems. On the other hand, the merger of two MBH could produce a
gravitational wave signal detectable, in principle, by the Laser Interferometer
Space Antenna (LISA). In the present work, we use the Press-Schechter
formalism, and its extension, to describe the merger rate of haloes which
contain massive black holes. Here, we do not study the gravitational wave
emission of these systems. However, we present an initial study to determine
the number of systems formed via mergers that could permit, in a future
extension of this work, the calculation of the signature in gravitational waves
of these systems.
