UPDATE 11AM: The upcoming fifth season of Mad Men is now slated to debut in March 2012. That is 17 months from the series’ fourth season finale. While the protract ed negotiations between Mad Men creator/ exec producer Matt Weiner and AMC/Lionsgate TV led to the acclaimed series’ pushed production start and, in turn, caused the show to miss its original July premiere date, the new March return date is not directly tied to the contract talks. According to sources with knowledge of the negotiations, Weiner had been actually pushing for a shorter gap between Seasons 4 and 5 and had stated that he could get Season 5 produced and delivered on budget for a 2011 premiere. However, I hear AMC’s argument was that it has now 5 original series to accommodate and its next available slot for Mad Men was in March 2012. Mad Men was AMC’s first series, which put the cable network on the original programming map. Since then, AMC has successfully launched several other series, most recently The Walking Dead, which supplanted Mad Men as the network’s highest-rated show.

PREVIOUS 8AM: Despite not having a deal with Mad Men creator-executive producer Matt Weiner yet, AMC is officially moving ahead with a fifth season of the Emmy-winning period drama, exercising its option with the series’ producer Lionsgate TV. (The cable network made a similar move two years ago when, along with Lionsgate, it was again embroiled in difficult renegotiations with Weiner.) Because of the protracted talks with Weiner, referred to in a statement by AMC as “key non-cast negotiations,” the premiere of Season 5 is being pushed from the summer to early next year. Here is the full statement: “AMC has officially authorized production of season 5 of Mad Men, triggering our option with Lionsgate. While we are getting a later start than in years past due to ongoing, key non-cast negotiations, Mad Men will be back for a fifth season in early 2012.”

Weiner is poised to become the highest-paid showrunner on basic cable with a new mega deal that would pay him close to $30 million over three years. But the lengthy negotiations, which have put Season 5’s start of production on hold, may have hit a snag in the final stretch. As we reported last night, Weiner is objecting to three things AMC/Lionsgate are asking for: integrating product placement into the series, cutting two minutes from each episode’s running time in favor of more commercials, and eliminating/reducing two regular cast members to save money. Meanwhile, also factoring into the negotiations is the pending spinoff of AMC, IFC, We and Sundance Channel into a standalone unit by parent company Rainbow Media.