The paradigm of mobile agents reached its popularity and attraction from typical application scenarios, which are located in the area of electronic commerce. In these common application scenarios, mobile agents get a task from its owner to buy certain goods. To fulfill this task, the agent wanders to various merchants and collects information about the different offers.In this paper we present an architecture that allows mobile agents to autonomously and automatically negotiate with vendors about offers. The approach allows evaluating multiple issues of an offer, such as price, guarantee or shipping fees, by special scoring functions.The process of negotiation in the area of electronic commerce is competitive. Thus the agent platform must avoid, that vendors can spy which tactic and strategy the mobile agents use. To ensure the relevant information for the negotiation mechanisms and functions we use a pair of cooperating agents to achieve a secret splitting.