The networks have flirted with the idea of a 12-month schedule for years, but none has made a serious commitment to the concept.

Now fourth-place NBC, scrambling for any way to gain a competitive advantage, is not only promising to institute a year-round schedule, but it has also nixed the traditional upfront presentation in order to get its schedule in front of media buyers earlier than the other broadcasters.

The network announced the changes yesterday, weeks after NBC Universal CEO Jeff Zucker first floated the idea of canceling the network’s elaborate annual upfront presentation during the thick of the writers’ strike.

Under the new system, NBC will introduce a 12-month schedule in April, giving it a one-month jump on the other Big Five networks, who will present their schedules in May. That will be followed by individual meetings with advertisers in New York, Los Angeles and Chicago, where NBC Entertainment co-chairs Marc Graboff and Ben Silverman will be on hand to answer questions.

NBC will still hold a smaller event in New York on May 12, its traditional upfront date, but it will be much less elaborate than past years and will focus on advertising opportunities across NBC Universal properties, including cable, Telemundo and digital.

In fact, yesterday the new presentation style was already drawing comparisons to cable, which also schedules year-round and unveils its schedules well before broadcast.

NBC’s aim is twofold. The network, which has seen its annual upfront tally tumble by more than a third from $3 billion five years ago, is hoping to get a jump on the other networks for upfront negotiations. It’s also pursuing less-traditional means of revenue, such as a recent deal with Ford for the movie “Knight Rider,” which did so well last weekend that Silverman said yesterday it will likely return as a full series.

The network also intends to get input from advertisers about its schedule, hoping that will save it from embarrassing flops such as 2006’s “Kidnapped,” which received little advertiser or viewer support despite good critical reaction. NBC may tweak the shows accordingly.

But the network’s approach could also be a sign of things to come for the other broadcasters. With TV ratings falling and an increasing amount of new media distractions competing for viewers’ attention, many think it’s impractical for the broadcast networks to effectively go dark for three months out of the year.

In recent years, the networks have taken to programming almost wall-to-wall reality during the summer months, but even the biggest summer reality hits draw much lower ratings than regular-season fare. Though Fox did attempt to roll out a full summer schedule four years ago, the network quickly abandoned that strategy after its scripted shows drew dismal ratings.

Meanwhile, cable networks have had tremendous success during the summer, often with highly regarded scripted shows like TNT’s “The Closer,” USA’s “Monk” and FX’s “Damages,” disproving broadcast’s long-held belief that people won’t commit to serials in the summer.