Samuel L. Jackson has closed a deal for a little more than $5 million to star in the Arnon Milchan/Mandeville Film co-production of “The Negotiator,” sources said. Kevin Spacey is said to be getting a bit more than $4 million to join the actor in the film, which will be distributed through Warner Bros. The paydays are significant increases for both actors.Directed by Gary Gray (“Friday”), the project will go before the cameras in late August or early September. Set in Chicago, “The Negotiator” is about a hostage negotiator who is set up for murder and tries to clear his name by taking a group hostage to smoke out the guilty party. Jackson entered into talks for the lead role after Sylvester Stallone decided not to do the project last month. Stallone still has a commitment with Warner Bros. Jackson has back-to-back films, with Barry Levinson’s “Sphere” and then playing an arms dealer in Quentin Tarantino’s “Jackie Brown.” Spacey, who last directed Miramax’s “Albino Alligator,” returns to Warner Bros., where he starred alongside Jackson in the Joel Schumacher-directed “A Time To Kill.” Jackson is repped by ICM’s Toni Howard and Addis-Wechsler’s Julie Silverman-Yorn and Eli Selden. Spacey is repped by WMA’s Brian Gersh and newly minted manager at Addis-Wechsler Geyer Kosinski.