By Nick Higham BBC media correspondent

Sir Trevor McDonald is News At Ten's long-serving presenter

They called it "News at When", and virtually everyone involved agreed it was a disaster. Now at last the decade-long saga of where to schedule ITV's late evening news finally seems to have come to an end.

Greg Dyke, now the BBC's director-general but then chief executive of LWT, was one of the ITV moguls who first floated the idea of moving News at Ten in the early 1990s.

ITV's flagship news programme still had a great reputation, but its famed centre advertising break could no longer command premium prices. News at Ten was costing the network money.

A sequence of entertainment programmes throughout the evening, unbroken by the news, made more commercial sense.

'Suffering'

But politicians, led by the then Prime Minister, John Major, protested that the main commercial network looked as if it was abandoning its public service remit, and ITV beat a retreat.

Five years later it tried again. David Liddiment, ITV's director of programmes at the time, recalled the network's thinking in a newspaper article last month.

"We were losing a third of the audience to other channels at 10pm and even more under-35s. Against a background of declining news viewing in general, News at Ten was suffering more than most."

The regulator, the Independent Television Commission, approved the change.

After all, in the intervening five years there had been an explosion in the number of channels and in the number of people able to watch them: dictating the scheduling of individual programmes, even programmes as central to a channel's character as the news, was going out of fashion.

So the late evening news moved to 2300, the early evening news to 1830, preceded by rather than itself preceding ITV's regional news programmes. Viewers were promised an end to the infuriating habit of splitting feature films in two, with News at Ten in the middle.

Then two things happened. The BBC, with Greg Dyke now at its head, stole a march on its commercial rival and moved its own Nine O'Clock News to Ten. Suddenly there was no weak spot in the mid-evening BBC schedule to target.

Meanwhile the audience for those early evening news programmes fell off a cliff. The ITC intervened after a year and instructed a furious ITV to do something, anything, to remedy the situation.

Unhappy

The result was the present unhappy compromise: a bulletin at ten three times a week, but otherwise at any time that suited the schedulers.

Not surprisingly, News at When's audiences have suffered: for traditionally-minded viewers news shows are "appointment-to-view" programmes, but it's hard to make an appointment when you don't know what time they're on.

In the first six months of this year ITV's late evening news averaged 3.5 million viewers; the BBC's Ten O'Clock News averaged 5.3 million. And viewers were not only confused but short-changed, with flagship news bulletins running head-to-head three nights a week.

So next year the ITV show will move again, to a regular five nights-a-week fixed slot at 2230. Network and regulator alike are licking their wounds.

The ITC, soon to be replaced by the new super-regulator, Ofcom, has discovered just how little power it has to dictate scheduling in the face of commercial realities.

And ITV has discovered how easy it is to throw away decades of audience goodwill and brand loyalty by an ill-judged decision, and how costly in terms of lost viewers and lost revenue.