The SEC said the bank's Citigroup Global Markets unit misled investors about a $1 billion collateralized debt obligation by failing to reveal it had "significant influence" over the selection of $500 million of underlying assets, and that it took a short position against those assets.
It said one experienced CDO trader called the portfolio "possibly the best short EVER!" while an experienced collateral manager said "the portfolio is horrible."
According to the regulator, the CDO, Class V Funding III, defaulted in November 2007, fewer than nine months after it closed, leaving investors with losses even as Citigroup made $160 million of fees and profits.
"The securities laws demand that investors receive more care and candor than Citigroup provided," SEC enforcement chief Robert Khuzami said in a statement.
Citigroup settled with the SEC without admitting wrongdoing. The SEC also filed charges against Brian Stoker, who it said was the Citigroup employee primarily responsible for structuring the transaction.
Neither Citigroup nor a lawyer for Stoker were immediately available to comment.
The SEC said it settled separate charges against Credit Suisse Group AG's asset management unit, which was the collateral manager for the CDO, as well as Samir Bhatt, the Credit Suisse portfolio manager mainly responsible for it.
Credit Suisse will pay $2.5 million to settle, while Bhatt agreed to a six-month suspension from associating with an investment adviser, the SEC said. Neither admitted wrongdoing.
The settlement is the third by the SEC against a major bank it accused of marketing a CDO, and then betting against it or allowing others to do so.
As part of the settlement, Citigroup will give up the $160 million of alleged improper fees and profits plus $30 million of interest, and pay a $95 million fine.
The settlement requires court approval. The case was assigned to U.S. District Judge Jed Rakoff in Manhattan, who chastised the SEC and ultimately rejected its proposed $33 million settlement in 2009 with Bank of America Corp over that bank's purchase of Merrill Lynch & Co. He later grudgingly approved a revised $150 million accord.
(Reporting by Karey Wutkowski in Washington, D.C., and Jonathan Stempel and Grant McCool in New York; Editing by Tim Dobbyn)