Citigroup said its forex head Anil Prasad will leave the bank to ‘pursue other interests’. Prasad will remain until the end of March and a successor will be announced in coming weeks. The departure is not related to the wider investigation into the alleged manipulation of currency benchmarks, according to a person with knowledge of the situation. Regulators are probing whether traders at the world’s largest banks colluded through instant-message groups to manipulate benchmarks such as the WM/Reuters rates. Citigroup controls about 15% of the world’s currency trading, second only to Deutsche Bank. The bank is the top-ranked trader in spot and emerging-market currencies. The bank has fired, suspended or put on leave at least 20 traders since reports emerged that employees at some firms shared information about their positions with counterparts at other banks.