Morgan Stanley agreed to sell its oil-storage business to NGL Energy Partners for $200 million, marking the latest step in Wall Street's retreat from the commodities business.

NGL Energy, which transports and markets crude oil and natural-gas liquids, will buy Morgan Stanley's ownership interests in its TransMontaigne unit, as well as related inventory. Tulsa, Okla.-based NGL Energy also will assume Morgan Stanley's obligations under certain terminal storage contracts, the Wall Street firm said Monday.