(Reuters) - Citigroup Inc on Tuesday posted an $18.3 billion quarterly net loss on one-time tax charges, but said adjusted income rose 4 percent from a year earlier as consumer businesses made up for lower revenue from bond and currency trading. The loss for the fourth quarter was due to a $19 billion write-down on the value of deferred tax assets left from losses in the financial crisis and $3 billion of expenses for the new U.S. tax on past profits earned and kept abroad.