NEW YORK/LONDON (Reuters) - Citadel, one of the world’s largest hedge fund managers, is replacing its head of crude oil trading, according to two sources familiar with the matter, after what one of the sources said were disappointing returns under his leadership. Chicago-based Michael Forsyth, who had been at the company 11 years, left last week along with members of his team Jason Stanley and Peter Debaz, the sources said. Forsyth will be replaced by Jonah DiPane, a trader from global merchant Castleton Commodities International, later this year, one of the sources said.