In September 2007 it established subsidiary MOEX Offshore 2007 LLC which entered into a partnership with BP for drilling in the Gulf of Mexico. On April 20, 2010, its rig the "Deepwater Horizon" exploded and sank, causing a massive oil spill. In May, 2011, MOEX Offshore, having had a 10% stake in the Deepwater Horizon through a subsidiary, agreed to pay US$1.07 billion to settle BP claims against it over the accident. Some analysts had thought BP would realize a larger settlement from MOEX but there was also relief to have a first step toward resolving the multiple claims.