Sales of LG Electronics\' Optimus L Series smartphones topped 15 million units globally since its introduction in February 2012, the company said Friday. Global sales of Optimus L Series devices breached the 10 million mark in December last year, before adding sales of 5 million units, equal to sell a device every second over the past two months, LG said in an e-mailed statement. After its launch at Mobile World Congress (MWC) in February 2012, LG rolled out Optimus L3, L7, L5, and L9 in a serial order at around 50 countries in North America, Europe, Asia and Latin America. Building on the success of the predecessors, LG planned to unveil the second generation of Optimus L Series later this month at the MWC 2013 with an upgraded design and improved features. \"The new Optimus L Series 2 expands upon the design philosophy of the original series so we\'re quite confident that we\'ll have another hit on our hands,\" said Park Jong-seok, president and chief executive of LG Electronics\' mobile communications division.