Wintershall Erdgas Handelshaus Zug AG (WIEE) is a joint venture involving Wintershall, Germany, (BASF Group) and OAO Gazprom. Wintershall and OAO Gazprom started their broad-based cooperation in the gas sector in 1990. Since then, WINGAS GmbH & Co. KG has invested more than 3 billion euros in approx. 2,000 km of pipelines and underground storage facilities in Germany. Within the scope of this cooperation, WIEE was formed in 1993 for the purpose of supplying Russian natural gas to South-Eastern European countries and developing related investments in the respective countries. In the meantime, WIEE has supplied more than 48 billion cubic meters (bcm) of natural gas to Romania and more than 8 bcm to Bulgaria.
 
WIEE continuously examines ways of developing the gas infrastructure in its markets. One recent example of this is the activities of its joint venture, WIROM GAS S.A. (WIROM) which has acquired the gas distribution licences for the Romanian cities of Turnu Magurele, Alexandria, Oltenita and Giurgiu. WIEE is also examining international cross-border pipeline projects with the Romanian Transgaz S.A., Bulgargaz and Naftogaz of Ukraine.