Royal Dutch Shell will invest $800 million in geological exploration and production of shale gas in eastern Ukraine, Energy Minister Yury Boyko said on Wednesday. "The investment will reach $800 million. This is the first significant joint agreement which gives us an opportunity to increase gas production in our country in the nearest future," Boyko said after signing the contract between Shell and Ukraine's Naftogaz energy company. Ukraine, unhappy with its dependence on Russian gas, is seeking alternative energy sources, including shale gas. Boyko has said that Ukraine planned to start shale gas production in five to seven years. Industry analysts say that Ukraine holds Europe's largest reserves of shale gas and could produce 7 to 10 billion cubic meters a year of it.