Responsibilities
An internal producer is heavily involved in the development of, usually, a single game. Responsibilities for this position vary from company to company, but in general, the person in this position has the following duties:
Negotiating contracts, including licensing deals
Acting as a liaison between the development staff and the upper stockholders (publisher or executive staff)
Developing and maintaining schedules and budgets
Overseeing creative (art and design) and technical development (game programming) of the game
Ensuring timely delivery of deliverables (such as Milestones)
Scheduling timely quality assurance (testing)
Arranging for beta testing and focus groups, if applicable
Arranging for localization
In short, the internal producer is ultimately responsible for timely delivery and final quality of the game.