In this chapter we present an application and framework to automate multi-issue bilateral negotiation in e-markets. We address several challenges of a typical negotiation in an online marketplace, such as (i) how to elicit preferences from users; (ii) how to formally represent preferences that at the same time allow human users to express both qualitative and quantitative preferences; (iii) how to compute agreements which are mutual beneficial for both buyer and seller, i.e., outcome enjoying economics properties as Pareto-efficiency. The issue of preference elicitation is addressed with the help of an easy-to-use graphical interface hiding all the technicalities of the underlying framework. Preferences are then mapped to a logic language, that allows one to express preferences on both numerical and non-numerical features. We build a utility function on top of this logic language in order to permit the representation of relative importance among preferences, to evaluate the possible agreements and finally choose the one(s) enjoying the Pareto-efficiency property.