Gas exports to the Continent are regulated by long term take-or-pay contracts. The contracts are described and analyzed. We thereafter examine whether the most central European gas market, the German market, is integrated. Are there substantial price differences between gas from different export countries, and do prices move together? Time series of Norwegian, Dutch and Russian gas export prices to Germany in 1990-1998 are examined. Cointegration tests show that the different border prices for gas to Germany move proportionally over time, indicating an integrated gas market (the Law of One Price holds). We find differences in mean prices, with Russian gas being sold at prices systematically lower than Dutch and Norwegian gas. Among the explanatory factors for price discrepancies are differences in volume flexibility (swing) and perceived political risk.