CORNING, N.Y., June 5 -- Corning Inc. has begun implementing a major portion of the restructuring plans it announced in April with a series of workforce reductions across its telecommunications segment and in several research and development facilities. By the end of this week, the company will have eliminated approximately 1,500 jobs and offered early retirement packages to some 600 employees. Corning began notifying employees at the Sullivan Park research facility and in the optical fiber and photonic technologies businesses that about 600 positions in Corning, N.Y., are being eliminated because of the downturn in the telecommunications industry over the past year. In late May, the company notified Corning Cable Systems employees in its Rio Grande, Puerto Rico, plant that the facility will close by the end of the first quarter next year, affecting 450 positions. Corning has proposed eliminating 250 positions at its Corning Frequency Controls operations in the US, Germany, Canada and China. An additional 200 positions will be eliminated across the company's Photonic Technologies business, inclusive of the closing of Corning's Albuquerque Development Center and the Photonics Research and Technology Center in Somerset, N.J., as part of its plan to consolidate research efforts. The company also announced it has sold its Appliance Controls Group, a part of Corning's controls and connectors business, to Jacobson Partners of New York for an undisclosed sum.