EMMIL — E-Marketplace Model Integrated with Logistics — represents a new approach to B2B e-commerce. EMMIL structures bring together three entity types — seller, buyer and third party logistics service provider — within the same transaction thus enabling combined total cost optimisation for purchase and delivery. We give an overview of the general principles of EMMIL then present the case of buyer oriented marketplaces in more detail. A composite procurement auction is introduced in which bids from sellers of goods and from logistics providers are combined. After formulating the optimisation problem we investigate possible solution methods for different scenarios.