In yet another blow to traditional news values, Ted Koppel, the host of ABC’s Nightline program for 25 years, has announced he’s leaving the network in December when his contract finishes.

Koppel and Nightline inspired a host of imitators around the world. Australian programs like Nightline on Nine and Lateline on ABC owe their inspiration one way or another to Koppel and Nightline.

But now he’s departing because the American ABC network wants to make Nightline more entertaining. That is, take the news out of Nightline and make it more entertaining to drive ad revenues higher. Why? ABC hopes to boost advertising revenues by around US$100 million by scheduling an entertainment program in the 11.35pm timeslot. That’s the figure US experts say Disney, owner of ABC, has foregone by leaving Nightline in the schedule and attracting a smaller audience.

And isn’t that what the Seven Network here is really planning to do on Sunday mornings by axing Sunday Sunrise and going with Weekend Sunrise, an idea pushed by the producer of weekday Sunrise, Adam Boland?

Three years ago, ABC tried to replace Koppel and Nightline with David Letterman. After the deal fell through, Koppel and ABC agreed to an overhaul of Nightline and ABC management has spent the past couple of months discussing plans to tizz it up. These have included a more informal style of production with an audience and low, nightclub style lighting.

Koppel told ABC that, at 66, he wasn’t the sort of host ABC wanted for a new program. ABC had hoped to keep him at the network on Sunday mornings, but he declined. Koppel has worked at the ABC for more than 40 years and Nightline started in 1979 when he hosted a program that monitored the Iranian hostage crisis each night.

When Nightline started, CNN was still struggling to make its mark and the US networks ruled the roost in news and current affairs. That’s no longer the case now that CNN, MSNBC, BBC World, and Fox News are all doing the same sort of work.