A state-run financial cooperative placed the highest bid for four units of Woori Finance Holdings Co. at the final auction early this week, gaining the upper hand over its two strong rivals in the government-led sale of the country's biggest banking firm, sources said Thursday. NongHyup Financial Group Inc. offered 1.2 trillion won (US$1.13 billion) to Woori Finance to buy Woori Investment & Securities Co., Woori Asset Management Co., WooriAviva Life Insurance Co. and Woori FG Savings Bank in the binding bid made on Monday, the bank's officials with knowledge on the matter said.