This article presents a procurement-based user association scheme for LTE-advanced HetNets. The proposed scheme enables LTE macrocell (LMC) to leverage capacity from femtocells (FCs) and fulfill the excess demand of the registered LMC (rLMC) users. Additionally, we propose an energy-efficient and quality- of-service (QoS)-ensured resource allocation scheme for rLMC users. Although the existing solutions capacitate 2G/3G-based cellular networks to leverage resources from complementary networks, such as WiFi, they are not well suited for LTE-advanced networks because of the different architectures. Moreover, the existing solutions are centered on rate-adaptive resource allocation, which is limited in capability of offering guaranteed bit rate (GBR) services to the rLMC users. The proposed scheme has manifold notable features. First, unlike the existing solutions, it implicitly ensures QoS of offloaded rLMC users. Second, it encourages competition among FCs, which results in cost-effective user association for LMC. Third, it is adaptive to the stochastic nature of users' demands. Finally, for data rate calculation, we use lookup tables in 3GPP standards for LTE-advanced. This makes the approach practically implementable in LTE-advanced HetNets. Numerical simulations of the proposed solution and the corresponding insights of the results justify the suitability of the proposed scheme for LTE-advanced HetNets.