South Korea's two biggest conglomerates have expanded their presence, with their earnings accounting for over 80 percent of the profits of the top 30 business groups last year, data showed Sunday, in the latest sign of their concentration of wealth. Samsung Group and Hyundai Motor Group posted a combined net profit of 34 trillion won last year, down 4 trillion won from the 38 trillion won in 2010, and the earnings from the remaining 28 conglomerates dipped to 8 trillion won from 42 trillion won over the cited period, according to the data compiled by CEOScore, a research firm that tracks conglomerates.