When I do PR, I'm usually interested in turning reporters on to a story. For lots of corporate communications people, though, the problem is the reverse: they want to put journalists off the case. Sharyl Attkisson at CBS News has a story on this very topic:
News reporters hate to hear that their story is "old news." It makes them want to drop the subject like a hot potato. So when a news reporter calls you about a potentially negative story — whatever it is — just say "it's old news" even if it's not.
The last tip is particularly fiendish. If the other tactics don't work with the reporter, go over their head and swing away at their boss.