  We consider the role of rescattering of secondary kaons on the dilepton
branching ratio of the phi meson. In-medium mass modifications and broadening
of kaons and phi mesons are taken into account. We find in the framework of a
Bjorken scenario for the time evolution of the expanding fireball that the phi
yield from dimuons is moderately or at least only slightly enhanced compared to
that from kaon-antikaon pairs. The relation to experimental yields measured by
the NA49, NA50 and CERES Collaborations at CERN SPS and the PHENIX
Collaboration at RHIC is discussed.
