Citigroup Inc. is firing back at Lehman Brothers Holdings Inc.'s "unprecedented" bid to cut off its right to hundreds of millions of dollars in interest payments tied to Citi's $3 billion bankruptcy claim against the failed investment bank, Dow Jones Daily Bankruptcy Review reported today. Lehman wants Bankruptcy Judge James Peck to end what it calls Citi's "interest rate arbitrage" with respect to rival claims on billions of dollars in assets. By provisionally paying off the bank, Lehman would stem the flow of interest payments to Citi, which could total hundreds of millions of dollars by the time the two sides face off in court, which isn't expected until 2015.