The immediate goal is for the parallel release to help start a potential new movie franchise. As television advertising becomes less effective because of declining TV viewership, movie studios need to reach a mass audience somehow, and having what amounts to ads sitting on store shelves is seen as a crucial antidote.

The effort is also a way for Warner to get more DVD bang for not many more bucks. The “Watchmen” film, Mr. Synder said, will probably generate at least three DVDs: “Tales of the Black Freighter,” followed about four months later by release of “Watchmen” itself, and then an “ultimate” edition in which the two are edited together into one megamovie.

Image In the movie Watchmen, Jesse Reid reads Tales of the Black Freighter, which will appear as a DVD within days of the film. Credit... Clay Enos/Warner Brothers Pictures

“The überfans of this property are going to go crazy for that,” Mr. Snyder said.

Warner has another reason to make nice with retailers. The studio, under added scrutiny from Wall Street now that its corporate parent plans to spin off Time Warner Cable, has annoyed chains by leading a movement in Hollywood to simultaneously release titles on DVD and on video-on-demand services.

Retailers worry that DVD sales will suffer from the lack of exclusivity, but Warner  which enjoys 60 percent profit margins for video on demand, compared to half that for physical DVD sales  says there is no cannibalization. Warner said this month that it would distribute many new releases simultaneously to DVD and on-demand services.

Warner downplayed any friction from the growth of video on demand. “Our retail partners haven’t seen a dramatic impact one way or another on their business, so they’re allowing us to work on it,” said Mr. Sanders.

Retailers seem to be taking a wait-and-see approach to Warner’s olive branch. Wal-Mart, the nation’s biggest DVD retailer, with as much as 40 percent of sales, declined to comment. Target, which has historically accounted for about 15 percent of DVD sales, said, “We’re always looking for opportunities to generate excitement in our entertainment business.”