Samsung Electronics Co. on Tuesday estimated its fourth-quarter operating profit at 2.8 trillion won (US$2.1 billion), down 35 percent from a year earlier. Revenue decreased 4.9 percent to 67 trillion won. The data for net earnings was not available. The operating profit was 29.3 percent lower than the average estimate, according to a survey by Yonhap Infomax, the financial data firm of Yonhap News Agency. The company will release its final earnings report later. (END) Source: Yonhap News Agency