A Snarkling wonders how many agents are on the payroll:
Do these rights agents handle all ancillary rights - or do some just do film rights? Back in the day, I only recall calling the main agent and then being able to get an answer on were they available - or not. I do not recall having to go to a third party just to find that out.And the couple times I had to start negotiations, the agents were with big agencies - Morris comes to mind - where they did that in-house.
Subsidiary rights. Everything that isn't the rights to publish the book in English in the world are called sub rights. So film agents are also sub rights agents, but the only sub right they handle is film. And most of them do only handle film. It's such a weird and bizarre biz out there in Movieland it's afull time job just keeping track of who's still in a position to buy.
Other sub rights like foreign rights can be handled by sub rights agents. Miss Snark has her colleagues in Greece, Albania, Turkey, Nigeria, and other exotic ports of call like Germany and France.
Your literary agent is the wrangler for all the rights but s/he will generally refer you to the film rights agent for questions. That's just how that biz works. I look like a Mafia don in front of Congress on those calls "I refuse to answer on the grounds I'll look like a nitwit".
And places like William Morris, and ICM, and now Trident, all have inhouse film folks. Miss Snark's version of an inhouse film agent involves her cell phone snapping pics of her ear.