By Tom Polansek CHICAGO (Reuters) – High-speed trader Infinium Capital Management, which has struggled financially, has stopped trading and is working to wind down the company, President Mark Palchak told Reuters on Thursday. Currency broker FXCM Inc and a subsidiary have acquired five trading desks, physical assets and 48 employees from Infinium to start a new joint venture, V3 Markets, Palchak and FXCM said. Palchak, who is chief executive of the new company, said the employees represented a majority of Infinium’s traders. It included approximately $11.9 million owed by Infinium to FXCM, according to the brokerage.