Citigroup and federal officials are in talks that could result in the US government substantially expanding its ownership of one of the world’s largest financial institutions. The Wall Street Journal reports the government could wind up holding as much as 40 percent of Citigroup’s common stock. The potential move at Citigroup would give the government its biggest ownership of a financial services company since the September bailout of insurer AIG, which left taxpayers with an 80 percent stake. Last week, Citigroup’s share price fell below $2 to an eighteen-year low.