Banks' metals-related revenues exceeded their earnings from the oil sector last year for the first time since 2014 as low and relatively stable crude prices discouraged hedging activity, but this is unlikely to be the start of a new trend.

Banks' commodity revenue has been on a steady downward path in recent years as they have exited or slimmed down their commodity businesses due to heightened government regulation and a poor performance from the sector.

The world's 50 biggest investment banks made revenue of $1.6 billion from trading, selling derivatives and other activities in metals last year, compared to $1.4 billion in oil, according to Coalition, a financial industry analytics firm.

That is the lowest for both in at least a decade and down from $3.9 billion for metals and $5.6 billion for oil in 2008 when the commodity supercycle peaked.

Oil-related revenue has dwindled since 2015 as a period of low prices reduced interest from producers and consumers in financial instruments that offer protection against price volatility, said Amrit Shahani, research director at Coalition.

Metals income held up better thanks to stable revenues from storing gold and silver and a surge in industrial metals prices since early 2016, and because fewer banks have left the precious metals business than have quit oil markets, Shahani said.

Oil-related earnings will likely rebound faster than metals over the next few years as banks focus on building revenues in the oil derivatives market, which is historically a much bigger business than metals derivatives, Shahani said.