Citizens Gas and Coke confirmed Thursday that it plans to close its Indianapolis Coke plant, citing declining sales and foreign competition.The company tried unsuccessfully to sell the facility, on Indianapolis' southeast side, and had previously told employees of possible layoffs. The decision to close it comes after the plant was on the market for nearly a year.The plant's 300 employees were notified of the closing early Thursday morning. The facility will be shuttered gradually over the next few months.Company officials blamed the closure on declines in the American steel and auto industries, significantly cutting demand for coke, a fuel made from coal used by steel mills and foundries."This is a very sad day for all of us at Citizens Gas and Coke Utility," said Carey Lykins, the company's president and CEO in a statement released to the media. "The decision to close Indianapolis Coke was an extremely difficult one because of the impact the plant closing will have on the plant's employees and their families."Losses have mounted in recent years. Officials said the company lost almost $18 million in 2006.Officials said about 20 possible buyers had been contacted over the last year and that negotiations were ongoing with one buyer for about five months before the deal fell through.Employees will get severance pay and help to find another job. Other employees are being offered an early-retirement plan.The future of the 120-acre plant has not been determined.