Citigroup raised fees in the foreign-exchange prime- brokerage business earlier this year, in some cases by as much as 25 percent. The bank provides clearing, settlement and financing to clients such as hedge funds, high-frequency trading firms and retail foreign-exchange brokers. Sanjay Madgavkar runs the business for Citigroup and reports to the global head of foreign-exchange and local markets, Nadir Mahmud.