At least two more traders have left Singapore-listed Noble Group (NOBG.SI) from its London energy desk this year, oil trading sources said on Friday.

Noble did not respond to a request for comment.

One of the departing traders was the firm's top distillates trader and the other was on the freight desk, the sources said. 

Some said at least three traders have left since the start of January.

Nobel's head of energy trading Rupert Tanna and top gasoline trader James McNicol left after Nigeria censured the firm over fuel imports late last year.

Noble had hired aggressively since it began trading in 2009 and recruited prominent traders from oil trading houses such as Vitol, but then closed its global liquefied petroleum gas desk in the middle of last year.