Since the credit crisis began last summer, we've seen this sentence one too many times:

"One of the highest-profile women on Wall Street will step down from her position."

And yet we write it again. Citigroup's Sallie Krawcheck, one of the highest-profile women on Wall Street, will step down, according to the Wall Street Journal. She heads Citigroup's wealth-management unit, which is being moved into the bank's institutional group as a part of a broad restructuring.

The circumstances and timing of her departure are still unknown, although the Journal does report that Krawcheck does not have another job lined up. Citigroup has had a number of high-level departures since Vikram Pandit stepped into the chief executive spot late last year.

Krawcheck was recruited by former chief executive Sandy Weill in 2002 to run the Smith Barney business. She rose to become the bank's chief financial officer for three years until 2007, when she was moved to the head of Citi's wealth-management business as part of an overhaul of the bank's top ranks.

This is just the latest in a string of senior-ranking female departures on Wall Street. Last November, Zoe Cruz was asked to resign from her post as co-president of Morgan Stanley after the department she oversaw made a series of disastrous subprime trades.

And then in June, Lehman fired its chief financial officer Erin Callan after investors raised questions about the bank's financial statements. Lehman's bankruptcy filing early last week is seen by some as vindication for Callan.

With Krawcheck out, there are few women left within the top ranks of any of the major financial firms. Of course, as this credit crisis continues to play out, there are fewer and fewer firms left on Wall Street at all.