U.S. investment bank Morgan Stanley is restarting its base metals trading business after withdrawing four years ago, Reuters reported Dec. 17, citing sources familiar with the matter.

The revived business will focus on market-making and services for clients such as hedging, and it hired about four people in London, including from rival JPMorgan Chase & Co. and trading house Trafigura Pte. Ltd., with plans to secure additional staff, according to the sources.

Morgan Stanley's move comes as rising volumes and instability in industrial metals improved revenues for investment banks following years of lackluster market conditions. The bank shut down its base metals trading operations around the end of 2015 as part of a plan to lay off up to 25% of jobs in its fixed income and commodities division.