LONDON—The U.K.'s financial regulator said firms that trade commodities, from oil to gold, have learned little from recent high profile cases of market abuse and are failing to adequately monitor the risks of such abuse.

The Financial Conduct Authority said in an online newsletter that the commodities trading firms that it reviewed were complacent over the risks of market abuse. The FCA review also found that commodities specialists had lower levels of monitoring and managing of their credit, liquidity and market risk than other parts of the financial services industry.

In recent years the finance industry has been roiled by several cases of large scale market abuse, many centering on London. That included the manipulation of the foreign-exchange markets, wrongdoing in the settling of key interest rates, and the manipulation of the setting of a gold benchmark.

"Many firms had not embedded the lessons learned from recent market abuse cases," the FCA said in its Market Watch newsletter posted on its website. "In some firms we found complacency toward the risk of market abuse."

The FCA conducted a review into 12 firms that act in oil, energy, metals and soft commodity markets, such as sugar and wheat. The review comes after recent changes in the market, in which a number of large banks, such as Barclays PLC and Credit Suisse Group AG, left commodity markets.

The FCA said that many firms believe that commodity markets were "'too deep, too liquid, and there are too many participants'" for them to be manipulated. The London-based regulator said that this ignored a number of abuse cases in markets as deep, or deeper, and past cases in commodity markets.

Some of the biggest rogue trading scandals have happened in commodities, including $2.6 billion in losses in the copper market chalked up by a trader at Japan's Sumitomo in the late 1990s.

At the majority of firms reviewed by the FCA, traders and brokers had a poor understanding of their responsibilities on the use of inside and market sensitive information. The FCA said it saw instances where information was being used to trade around infrastructure outages and equity that had not been checked to make sure it was appropriate.

Most firms had not carried out an assessment over whether they had adequate monitoring and surveillance of such potential abuse, the newsletter said.

The companies were also failing to identify suspicious transactions and escalate them to the FCA through Suspicious Transaction Reports (STRs). Banks, and other financial services firms, are asked by regulators around the world to submit such reports across their business, from suspected money laundering to potentially illegal trades. The FCA said that only two of the 12 firms in the sample had submitted STRs relating to commodities trading, although many had described events and market behavior that may have requited such submissions

The FCA also said that many firms were also failing to monitor their own risks. That includes safeguarding against potential credit and liquidity risks, in which a company could become over exposure to debt and markets and in managing their own access to liquidity, or finance.

Write to Alistair MacDonald at alistair.macdonald@wsj.com

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(END) Dow Jones Newswires

September 04, 2015 12:25 ET (16:25 GMT)