Adaptive Virtual Environments have been developed aiming at generating 3D environments adapted to user's necessities and interests. Navigation aid techniques and content adaptation improve user interaction in such environments. This article presents a system for supporting real time adaptive virtual environments. A multiagents architecture is used to manage contents updating in the virtual world according to user profile evolution. Its agents utilize the User Model, the Environment Model and a 3Dobjects database for decision-making on the necessary updating. A manager agent is responsible to accompany the user's actions through the user interface to collect information that may be used to update his/her profile. This agent also controls the communication between agents.