The studios and other large production companies are signatory to the Writers Guild. This means they have agreed to use Writers Guild-approved contracts. Their names can be easily found in a variety of directories.
What are large producers looking for?
Their perceived needs can change monthly, or even weekly. They are constantly assessing the markets for the right formula. In general, they want something that can be easily pitched to other producers, studios, distributors and moviegoers. So the concept or central idea must grab them immediately.
They also want something written for the actor. They want a script that makes the difference between Bruce Willis doing the movie and Tom Cruise doing it, or Julia Roberts as opposed to Lindsay Lohan.
We must be aware that when a producer produces the script of a new writer, he's putting his job on the line. If the resulting movie fails, he could be canned for trying someone new. Whereas if a film using a proven writer fails, it can be seen as a fluke.
When a producer hires you, she's hoping you're up and coming.
These large producers have deals with studios, meaning that they have contractual agreements to produce a certain number of pictures with a studio or production company, or a studio may have first right of refusal. This is another reason why its better to let a producer take your project to a studio than go directly to the studio yourself. These producers are big because they have the money needed to finance a film.
Generally, large producers accept scripts only from agents.
However, if your query is strong enough, there are some WGA-signatory producers who may accept a script without an agent. In such cases, they may require a submission agreement or release. A submission agreement is a legal document is a legal document that basically absolves the producer or executive of responsibility if your work is accidentally stolen. It sounds horrible, but you should consider signing the release to get your work sold and produced.
Generally, these folks aren't interested in stealing your story. Theft occurs occasionally, but large producers are more interested in avoiding lawsuits than they are in a theft. Writer's paraonia is the hallmark of an amateur.You've got to get your ideas out there. Perhaps your best protection is your writitng ability, industry savvy and completed script.