Three weeks ago, HBO and Sci Fi Channel announced new projects featuring top theatrical stars. Brad Pitt and Edward Norton are attached to the 10-part HBO miniseries “Lewis and Clark” and Nicolas Cage is attached to a Sci Fi paranormal detective series, “The Dresden Files.”

In both cases, however, the actors are not acting. They’re producing and … that’s about it.

The phenomenon of “stunt casting” is a time-tested tradition for networks looking to give a series a special promotional kick. But the benefits of stunt producing-having a popular actor produce a project while not appearing on camera-are much murkier.

For one thing, if an actor’s job is acting, what he or she brings to the table as a producers is questionable. Mr. Pitt, for example, landed the 10-part HBO mini without ever producing anything before (at least nothing that has yet been released, according to the Internet Movie Database).

Industry experts agree that viewers are not somehow fooled into believing that being produced by an actor is a hallmark of production quality for a movie or series. But they also note that the practice can yield less obvious benefits, especially for cable networks clamoring to be on a viewer’s set of channels under regular consideration.

“It definitely helps elevate your profile,” said Mark Stern, executive VP of original programming for Sci Fi. “And since we have limited marketing dollars, attaching an interesting name can help tremendously.”

In other words, Mr. Cage may not be on screen during the “The Dresden Files,” but when the premiere rolls around he presumably will be available to walk the red carpet and give interviews, bringing more press attention to the project.

Unlike stunt casting, which is used across the board in television, most examples of stunt producing are found on cable: Bruce Willis producing “Touching Evil” for USA; Courtney Cox Arquette producing MTV’s upcoming “Dirt Squirrel” and the TBS pilot “Daisy Does America”; Whoopi Goldberg producing “Strong Medicine” for Lifetime; George Clooney producing “K Street” and Mark Wahlberg producing “Entourage” for HBO.

The benefits of stunt producing to cable are in many cases similar to those of the better-documented trend of name actors taking their pet projects to cable. For actors strictly working as producers, the concept received its first major push when HBO partnered with Tom Hanks for “From the Earth to the Moon” and “Band of Brothers,” two blockbuster miniseries for the network.

One advantage of both, sources said, is that a name actor can sometimes bring in his wake a talented behind-the-camera team-in the case of Mr. Hanks, his friend Steven Spielberg, who was also an executive producer on the project. But the same also works in reverse: For producers, having a name actor in tow can help land a deal.

“It’s always easier to get a meeting and close the sale with an actor attached,” said cable consultant Ray Solley. “The thinking of cable networks is: ‘I want to be in business with these people down the line.’ If I want to cast them in something, I’ve got a favor to turn in.”

For agents, however, putting a star in a room with mere cable TV executives can pose a problem. A top agent familiar with television packaging noted that having a star attached as producer makes the project easier to sell, but added that the agent must manage the situation carefully to avoid bruised egos.

“Most agents won’t put an actor in a room unless they know it’s a sale in advance,” the agent said. “If Mel Gibson is walking into a room, we’re gonna make sure they’re buying it.”

Network executives and industry observers disagree on whether channels sometimes sign actors’ producing projects with the secret hope of getting them on camera. “The possibility of getting some of these names on camera, by hook or by crook, is never far from an executive’s mind,” Mr. Solley said.

The agent agreed. “There’s little reason to say no,” she said. “It’s just development-let’s see how they do. Because they’re hoping the actor will help them down the line.”

But Jeff Cusson, a spokesman for HBO, said an actor’s projects are developed based only on the merits of the project.