Intelligence, collaboration and mobility are the main important features in designing agents for electronic commercial systems. But very few systems permit to implement agents which have all these characteristics. The authors address the problems of designing intelligent collaborative mobile agents. They propose a componential approach for designing and implementing such agents. The framework architecture for agents dissociates the components expressing the internal behavior of an agent from the components expressing coordination between agents in order to enhance modularity and reusability. They have developed a component description language for easy modeling of componential agent architecture. The component specification is automatically translated into Java source code by the compiler, and then integrated into a mobile agent platform. They have tested the agent development system with the Travel Agency scenario, one of the standard electronic commercial service examples.