This paper describes a solution for inter-domain QoS to be part of the framework for end-to-end QoS control. The solution is based on the use of virtualtrunk type aggregates, defined by means of Service Level Agreements, for data transport between peering domains. These aggregates are defined for several "well-known" traffic classes, supporting different types of applications. We define an extension to the BGP routing protocol to transport three different QoS metrics (light load delay, assigned bandwidth and a congestion alarm), and a path selection algorithm using a combination of these metrics. Simulation results demonstrate the use of our solution, showing that it yields much better QoS results than those achieved with standard BGP or BGP with the QoS_NLRI extension, since it is able to efficiently avoid congested paths, reducing delays and packet losses. Moreover, these results are achieved without significantly affecting route stability.