ISTANBUL (Reuters) - General Electric has already invested more than half of the $900 million it has earmarked for Turkey on projects ranging from energy to healthcare to locomotive production, Chief Executive Jeff Immelt said on Thursday. The investments totaling $515 million include supplying turbines for a 35-megawatt wind farm and gas turbines for an 840-megawatt power plant, both to be operated by GE's Turkish partner, Gama Energy, when they start up in 2014 and 2016. The investments by GE, which were announced in early 2012 and will span three years, should boost Turkish manufacturing and slash the country's import bill. The current account deficit is almost $60 billion. Other GE investments include facilities to make bladed disks, or blisks, for the LEAP engines built by a venture between GE Aviation and Snecma of France, Immelt said. The disks, which will be exported worldwide, will be made by a joint venture between GE and state-run Turkish Aerospace Industries (TAI). GE, the world's top manufacturer of airplane engines and diesel locomotives, owns a 46 percent stake in TAI. "This complements (the government's goal) to strengthen localized manufacturing and boost exports to drive the country's competitiveness," Immelt said at a signing ceremony. The investments include production of GE PowerHaul locomotives in Turkey, with a target of 50 units next year and eventually as many as 100 units annually, which could be worth exports of $1.5 billion in 10 years, Immelt said. Turkey has long sought to create a wind-turbine manufacturing base to harness its own wind potential, and Immelt said GE's investments in towers and blades in Turkey may eventually boost a sector to serve local and foreign markets. "We are investing in wind parts, and I see a very strong pathway to localizing wind-turbine production," he said. (Reporting by Ayla Jean Yackley; editing by David Evans and Anthony Barker)