A centralized market-splitting algorithm is implemented in this paper in a Europe-wide level, comprising both power pools and Power Exchanges, with each local/national market respecting the standard constraints imposed by its own regulatory framework, including the full set of unit technical/commitment constraints and system operating constraints in power pools. In view of the forthcoming large-scale RES penetration, physical markets with unit-based offers (either pools or PXs) check the feasibility of the electricity market solution against their internal (intra-zonal) transmission network constraints, considering full network topology. This is accomplished through an iterative process, iterating between the overall optimization algorithm, and intra-zonal power flows of the countries/regions, which identify possible congestions and incorporate additional constraints in the central pan-European market-splitting problem. The iterative process terminates when all internal transmission constraints are satisfied. Locational marginal prices (LMPs) can be computed in the physical markets, whereas zonal/system marginal prices are computed in markets with portfolio-bidding schemes. The proposed algorithm is tested in terms of computational efficiency using the full UCTE network.Index Terms-Internal electricity market, market splitting, mixed integer linear programming, power exchange, power pool, power transfer distribution factors.