(Bloomberg) -- The UK’s financial regulator fined ED&F Man Capital Markets Ltd. £17.2 million ($21.3 million) over its role in Cum-Ex tax transactions, the fourth London broker to be hit with a penalty over the controversial trades.

The Financial Conduct Authority said in a statement that the brokerage — a unit of global commodities firm ED&F Man Holdings — “enabled” significant volumes of dividend arbitrage trading that allowed millions of euros to be illegitimately claimed from Danish tax authorities. It’s the largest penalty to be levied by the UK watchdog so far.

“It is completely unacceptable for authorized firms to make money from this kind of trading,” said Therese Chambers, the FCA’s joint executive director of enforcement and market oversight. 

ED&F Man didn’t dispute the FCA’s findings and was given a 30% discount in the fine. 

Read More: London Fines Show Brokers’ Role in $1.9 Billion Cum-Ex Scandal

The FCA has censured three smaller London firms over the last two years for engaging in Cum-Ex trades on behalf of Sanjay Shah and his Solo Capital Partners hedge fund. Officials at the ED&F Man unit arranged the deals themselves, executing transactions between an unregulated proprietary desk based in Dubai and a group of US-based pension plans, according to the FCA. 

The brokerage executed dividend-tax trades on some £10 billion of stocks, including £4 billion tied to Danish equities, and generated £129 million of revenue.

The Danish tax authorities paid out more than £20 million to the firm’s clients in “illegitimate payments,” the FCA said.

The firm traces its roots to the 2012 decision by ED&F Man — better known for hauling sugar and coffee around the world — to establish a global markets division. The subsidiary acquired an equity-finance business from MF Global Holdings Ltd., the firm run by Jon Corzine that had collapsed the previous year, and began arranging dividend-tax trades, according to the FCA.

ED&F Man began to wind down the brokerage business last year and agreed to transfer its operations — such as clients and employees — to Marex Group in August. The business that oversaw Cum-Ex trades was not part of that deal, Emma Kane, an external spokeswoman for ED&F Man, said in an emailed statement.

“The FCA’s action relates to a legacy business area that was shut down” in 2015, Kane said. “It was specifically excluded from the sale of assets to Marex and is a contingent liability that was ring-fenced as part of that transaction.”

The FCA fine will make it possible to complete the closure of ED&F Man Capital Markets, Kane added.

Danish and German investigators separately raided the London offices of ED&F Man in November.

Cum-Ex took advantage of tax laws that seemed to allow multiple investors to claim refunds of a tax that was paid only once. Germany abolished the practice in 2012. Some traders then targeted Denmark in similar trades and the country has said it suffered a loss of more than $2 billion.

(Updates with detail throughout.)

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