Samsung Electronics said Friday it expects third-quarter operating profit of around 4.2 trillion won ($3.52 billion), a 13.6 percent fall year-on-year amid weak demand for flat panels and computer chips. The South Korean firm was publishing its earnings estimates before official results later this month. It tipped revenue of about 41 trillion won in July-September, a 1.9 percent rise from the third quarter of 2010. For the second quarter of this year, the company reported an operating profit of 3.75 trillion won on sales of 39.44 trillion. Samsung Electronics is the world\'s largest maker of flat panels, memory chips and flat-screen televisions and the second-largest mobile phone maker. It did not give an explanation for the figures or a net profit forecast in the earnings guidance. Analysts said falling demand for personal computers and televisions hit Samsung\'s chip and liquid crystal display business. But brisk smartphone sales likely helped to offset this. They said the company would benefit from strong demand for non-memory chips and advanced flat displays, mainly driven by brisk sales of mobile devices, as well as the won\'s recent fall against the dollar.