CNBC contrasts News Corp (NYSE: NWS)'s Rupert Murdoch's success grooming his son to take over from him with Sumner Redstone's failure to do the same.

I once wrote Redstone seeking a position as a merger adviser. That letter was ignored. But given all the misery that he causes those who work for him -- including his own family members -- I can see the brighter side of that rejection. Meanwhile Murdoch, for whom I have consulted, has done a masterful job of giving his children a chance to work in the business and letting the most talented of the lot rise up in the organization. And he's done this without losing his top talent.

By contrast, Redstone fired the talented Viacom (NYSE: VIA) CEO Tom Freston because he failed to secure a deal to acquire MySpace. And he's utterly failed to develop talented managers -- either from his own family or anywhere else for that matter.

He's certainly free to do whatever he wants, but he either thinks he's going to live forever or he simply doesn't want to give up power until the last bit of life ebbs from his skeletal executive presence.

Peter Cohan is president of Peter S. Cohan & Associates, a management consulting and venture capital firm. He also teaches management at Babson College and edits The Cohan Letter. He has consulted to News Corp.'s chairman and has no financial interest in the securities mentioned in this post.