Rosneft Chief Executive Igor Sechin, Russia’s most powerful oil official, signed a raft of deals Friday at the St. Petersburg International Economic Forum, including further production, exploration and refining agreements with BP. They come a day after another Russian energy company affected by sanctions, OAO Gazprom , OGZPY -1.82 % inked a preliminary deal with three European firms, including Royal Dutch Shell RDS.A -0.17 % PLC, to expand a pipeline to Germany. U.S. and European sanctions over Russia’s interventions in Ukraine prevent Rosneft from raising credit in the West or accessing Western technology for tapping shale and arctic reserves, but don’t prevent asset sales and purchases. The U.S. has also imposed personal restrictions on Mr. Sechin. The deals announced on Friday cement the strategic alliance between Rosneft and BP, which owns a nearly 20% stake in the Russian company. BP is taking a 20% stake in Taas-Yuryakh Neftegazodobycha in […]