UPDATED: Major studios are not the only ones objecting to the new guidelines for shorter movie trailers proposed by the National Assn. of Theater Owners. At least one prominent exhibitor, Cinemark, is rejecting the recommendations, raising the question of why NATO is pushing the issue at all.

The guidelines — which stipulate that trailers are not to exceed two minutes in length, as well as not to be played in theaters more than 150 days prior to a film’s release — were created on behalf of NATO constituents, who felt there was an over-emphasis by the studios on promoting summer blockbusters in the slower months rather than marketing the films debuting during that time.

Variety also has learned that AMC, the nation’s second-largest circuit, played a major role in pushing NATO on the trailer issue initially.

Now, one major exhibitor is saying leave well-enough alone — at least, when it comes to creating blanket industry guidelines.

Cinemark, the third-largest U.S. chain, issued a letter to studio execs Wednesday. In the correspondence, Cinemark CEO Tim Warner (pictured above) said the company “voted against these guidelines and against the issuing of the press release regarding these guidelines.

“Cinemark believes in a business-to-business relationship with the studios,” the letter continued to read. “As such, all marketing and related issues around marketing will be handled by Cinemark on a business-to-business basis. We will not allow NATO or any other entity to act on our behalf or speak on behalf of Cinemark.”

The letter also stated: “It is our firm belief that we as an industry need to work together focusing on how we can build and expand rather than creating issues that divide us.”

In its press release, NATO said: “The guidelines are designed to maximize the effectiveness and efficiency of the industry’s marketing efforts and to promote competition.” It went on to call the guidelines “completely voluntary and will be implemented through individual exhibition company policies, which may vary.”

Regal and AMC voted for the guidelines, though they will be working with the studios on a picture-by-picture basis.

AMC released a statement saying, “AMC Theatres is in full support of the voluntary NATO In-Theatre Marketing Guidelines, which at their core are about the more efficient and effective use of our industry’s marketing resources. Recently published letters, articles and commentary we’ve seen throughout the industry badly misrepresent the intent of these guidelines. As has always been our practice, this and all studio dealings will be handled directly with our distribution partners as we seek to maximize the box office performance of their films, and we expect that practice to continue.”

In addition to shorter trailers — which typically run two minutes, 30 seconds — and shrunken marketing windows, all other in-theater advertisements are limited to 120 days prior to release, as well. The guidelines allow for two exceptions per year, per distributor, however.

From a studio perspective, the call for shorter trailers specifically is a misguided attempt to increase the number of trailers shown in theaters, which, in turn, decreases their overall impact on audiences. That’s added to pre-show promotions, which studios feel are already too long.

Shorter marketing windows, meanwhile, create a distinct disadvantage for promoting non-franchise fare.

“I think there is a sort of naivete on behalf of those exhibitors,” said one studio marketing head. “Original movies take care, and anticipation is one of the most powerful tools we have in marketing.”

But rather than engage in a public back-and-forth, both studios and exhibs are insisting on continuing the conversation behind closed doors. Cinemark certainly does.

“With the new technology … we have worked with you to put in place (what) we think can revolutionize how we do in-theatre marketing,” Cinemark’s letter stated. “However, we assure you that these discussions will be done directly with you and your marketing teams and developed as a partnership to grow the business.”

Regardless of how the trailer topic began, one studio distribution honcho opined: “This is far from being over.”