(Adds details on Goldman's commodities business.)
NEW YORK, Jan 31 (Reuters) - Several key commodities traders are leaving Goldman Sachs Group Inc after the Wall Street bank posted one of its worst years in the business.
Those leaving include Don Casturo, operating chief of global commodities; Saad Usmani, a London-based managing director who traded crude oil and natural gas; and Rahul Dhir, who traded refined oil products, according to people familiar with the matter and a Jan. 30 memo announcing Casturo's departure seen by Reuters.
The sources requested anonymity because they were not authorized to speak to the media.
The departures are the latest wrinkle in an overhaul of commodities trading at Goldman, once among the largest players in the sector. Its chief executive, Lloyd Blankfein, spent the early days of his career at the bank selling gold.
Goldman hired several new senior traders late last year to turn around the business and replace people like Greg Agran, who left as co-head of commodities trading in September after 26 years with the bank.
Commodities was the main driver of a 30 percent decline in Goldman's broader bond trading business last year, Chief Financial Officer Marty Chavez said on Jan. 17.
The bank worked hard to reduce risk and manage stockpiles of assets that were hurting results toward the end of 2017, said Chavez, who had also worked in commodities trading. Goldman is focused on catering to clients rather than placing bets on price moves, he added, noting that trends are hard to predict.
"I remember when I was in that business and people would ask me, 'What do you think about the outlook for oil prices?" he said. "I would say, accurately but perhaps not all that helpfully, 50 percent chance they go up and a 50 percent chance they would go down."
Goldman is the only large U.S. bank that has continued trading and investing in commodities in a major way. Rivals including Morgan Stanley pulled back years ago after a public outcry over banks potentially influencing commodities prices, and as regulatory scrutiny increased.
Major commodities trading firms like Noble Group had to restructure and close divisions due to heavy losses, and funds including one run by longtime energy trader Andy Hall shuttered last year for the same reasons.
Casturo, the outgoing commodities operating chief, first joined Goldman in 1998. News of his departure was first reported by Bloomberg.
Among those who joined in recent months are Nitin Jindal, who became partner and head of North American natural gas and power trading, and David McKeon, formerly of Castleton Commodities International LLC, who is now a managing director and senior oil trader at Goldman. (Additional reporting by Marcy Nicholson; Writing by Lauren Tara LaCapra, David Gaffen and Renita D. Young; Editing by Nick Zieminski and Richard Chang)