Citigroup (NYSE:C) sues Barclays (NYSE:BCS) to recover nearly $142M related to foreign exchange trading amidst the Lehman bankruptcy. Citi claims Barclays promised to indemnify Citi against any losses from settling trades for Lehman between Sept. 17-19, 2008. Citi says it lost $580M during this period, but has reduced the amount (plus legal fees) to $141.8M.