(Bloomberg) -- A New York firm that managed billions of dollars for sanctioned Russian oligarch Roman Abramovich was sued by the Securities and Exchange Commission for not registering as an investment adviser.

The SEC filed suit Tuesday against Concord Management LLC of Tarrytown, New York, and founder Michael Matlin. The agency said Concord and Matlin’s failure to register meant they invested more than $7 billion in US securities markets with no regulatory oversight at all.

Abramovich wasn’t identified in the SEC suit, which described Concord’s sole client as a “wealthy former Russian political official” who was sanctioned by the UK and European Union in March 2022. Bloomberg News reported in March 2022 that much of the money behind Concord belongs to the oligarch, who was included in a wave of sanctions targeting allies of Russian President Vladimir Putin following the invasion of Ukraine.

The SEC asked for an order forcing Concord and Matlin to disgorge all ill-gotten gains from illegal conduct. According to the suit, the defendants received about $85 million in compensation, including about $50 million in performance bonuses, $29 million in fees and $6 million in reimbursed expenses, between 2012 and 2022.

Read More: Hedge Funds That Took Abramovich’s Billions Have No Way Out

“While we are disappointed with the SEC’s decision to pursue this non-intent-based claim, we are confident that a full and fair review of the applicable law and relevant facts will underscore that Concord Management and Michael Matlin complied with all regulatory and legal requirements,” the firm said in a statement.

A representative for Abramovich didn’t immediately respond to a request for comment.

Concord’s assets were frozen due to the sanctions, but the investments are active and the firm and Matlin could resume management if the freeze was lifted, the SEC said in its suit.

Matlin, 59, of Airmont, New York, is a US citizen who was born in Russia, emigrated to the US in 1988 and founded Concord in 1999, according to the SEC. The firm’s purpose was to provide supervisory and management services so that its client’s assets would be invested in a variety of US-based private fund investments, and it managed a portfolio with an estimated total value of $7.2 billion as of January 2022.

Concord mostly steered Abramovich’s money to the biggest and best-known US firms, including Brevan Howard Asset Management, Millennium Management and Carlyle Group Inc., people familiar with Matlin’s firm told Bloomberg. 

Abramovich, 56, who has a net worth of $7.3 billion according to the Bloomberg Billionaires Index, amassed his fortune from the sale of privatized assets acquired from the former Soviet Union, including oil giant Sibneft and Aeroflot. He became well-known in the UK in particular as the longtime owner of the Chelsea soccer team, which he sold in March 2022.

The case is Securities and Exchange Commission v Concord Management LLC, 23-cv-8253, US District Court, Southern District of New York.

--With assistance from Stephanie Baker and Jonathan Browning.

(Updates with statement from defendant in fifth paragraph.)

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