The Washington Post reports that Citigroup, Inc. (NYSE: C) has agreed to buy back $7 billion worth of Auction Rate Securities (ARS) it sold to its clients. Citi will also pay a $100 million civil fine. This is a great move for individuals and companies that bought this toxic waste. The question is -- will the rest of the $330 billion ARS industry follow Citi's lead?

Citi will buy back the debt from 40,000 customers around the U.S. by November 5. And the $100 million fine will be split -- $50 million to New York and $50 million to the North American Securities Administrators Association. Cuomo had accused Citi of "wrongly telling customers that auction-rate debt was safe, liquid and the equivalent of cash." It looks like current CEO Vikram Pandit wanted to clear the decks of a problem he inherited and in so doing help to clear Citi's name.

But the question is whether Cuomo -- having achieved this considerable victory for defrauded ARS customers -- will have the clout to clear the rest of the $330 billion worth of ARSs that were frozen. There are many other firms -- including Merrill Lynch & Co., Inc. (NYSE: MER) and UBS AG (NYSE: UBS) which have their own frozen ARS problems. And until all of these firms make their investors whole, a dark cloud will hang over their reputations.

This cloud could seriously damage their future prospects when the industry recovers a few years hence. The sooner the rest of the industry follows Citi's lead, the better.

Peter Cohan is President of Peter S. Cohan & Associates. He also teaches management at Babson College and edits The Cohan Letter. He owns Citigroup stock and has no financial interest in the other securities mentioned.