Deutsche Bank has prohibited its foreign exchange and fixed income staff from using online chatrooms, joining a growing band of lenders who have halted the use of such forums over concerns of mounting scrutiny from regulators. Chat rooms have been a focus for regulators investigating manipulation of benchmark interest rates and possible rigging in the $5.3 trillion-a-day foreign exchange market. We have banned the use of multi-party chatrooms in FX (foreign exchange) trading already in the first quarter, and we have extended this ban to other parts of our fixed income business, a Deutsche Bank spokesman said on Wednesday.