The collapse of the subprime-mortgage market in 2007 destroyed hundreds, maybe thousands, of financial companies that had ridden high on real estate's speculative fervor.

Others survived the meltdown, but have been on life support, their value all but extinguished. Among them was Philadelphia's Alesco Financial Inc., a lender to banks and insurance companies.

To salvage Alesco, the company's management is asking shareholders to approve a merger with Cohen & Co., a privately held Philadelphia investment bank, in a shareholder vote scheduled for Tuesday at the Cira Centre.

This is not a run-of-the-mill deal.

For one thing, Alesco and Cohen & Co. share an address, the 17th floor of the Cira Centre. They also have the same driving force - and largest shareholder - behind them: Daniel G. Cohen, who owns just under 6 percent of Alesco.

Cohen, 40, is the older son of Edward and Betsy Cohen, long-established figures in financial circles in Philadelphia and beyond. Betsy Cohen, founder of the former Jefferson Bank and member of some high-profile nonprofit boards, is the best known of the Cohens.

The Alesco-Cohen & Co. deal is an example of how members of the family - who at one point last year were involved in nine publicly traded companies they had started - roll with the economic punches, using public and private entities to get back on their feet.

Daniel Cohen, through a spokesman, declined to be interviewed for this article because of the pending shareholder vote. He has denied repeated requests to be interviewed since 2007.

He lives at least some of the time in Paris and fiercely guards his privacy. A graduate of Germantown Friends School, Daniel Cohen earned an undergraduate degree from the University of Chicago and in the mid-1990s was a doctoral candidate in ancient Chinese literature at the University of Pennsylvania.

Daniel Cohen is well-known in Philadelphia's financial community, but numerous interviews seeking on-the-record comments about him and his businesses came up dry.

In a June interview about her bank, The Bancorp Inc., of Wilmington, Betsy Cohen described Daniel Cohen as a "genius," after hearing of a similarly flattering comment about herself.

"He is exceedingly creative and very perceptive," she said.

But like most financial executives, Daniel Cohen did not foresee in 2006 the imminent bursting of the real estate bubble - until it started dragging down the publicly traded companies he was running.

Against that backdrop, the Alesco-Cohen & Co. deal recalls another related-company deal announced in June 2006, as the first significant cracks in the subprime world were showing.

That deal involved Daniel Cohen's Taberna Realty Finance Trust and RAIT Financial Trust, a Philadelphia company his mother had run conservatively for nearly a decade.

Taberna, which was spun out of Cohen & Co. in 2005, specialized in raising money for real estate companies through complicated instruments known as collateralized debt obligations. Those securities gained notoriety during the subprime-mortgage crisis for their supposed ability to turn junky residential mortgages into investments with triple-A ratings.

By the time Daniel Cohen took over from his mother as chief executive officer at RAIT with the completion of the merger in December 2006, the financial world, led by subprime-residential-mortgage lenders, had begun imploding.

In February 2007, Daniel Cohen assured investors that RAIT had little at risk in the subprime market. But in July of that year, he disclosed that RAIT had lost $95 million in the bankruptcy of American Home Mortgage Investment Corp., which was tied to the subprime-mortgage market.

RAIT was still cleaning up the mess this year. In June, for example, it sold for what the company described as "nominal consideration" four Taberna investment vehicles it had seeded with $236 million.

RAIT's market value has plummeted from $2.4 billion in February 2007 to $88 million now. Last week, a federal judge in Philadelphia approved a $32 million settlement of shareholder claims that RAIT had failed to disclose subprime-mortgage-related risks.

Daniel Cohen resigned as chief executive of RAIT in February, when the deal between Cohen & Co. and Alesco was announced.

Alesco was launched in 2005, with Cohen & Co. managing its assets. Alesco went public in 2006. Its value peaked at $652 million in January 2007.

In May 2007, Daniel Cohen spoke to Alesco investors of "turbulence and temporary impairments in mortgage business." By early August of that year, it was clear that Alesco was in deep trouble. Its market value as of Friday was $33 million.

The merger of Alesco and Cohen & Co., closely linked companies with separate owners, not only will help Alesco - which has reported $1.3 billion in net losses since the second quarter of 2007 - but it also will give Cohen & Co., which Daniel Cohen founded in 1999 with his brother, Jonathan, a relatively easy way to become a publicly traded company.

Cohen & Co. has its own problems, with revenue from work related to new issues of debt falling from $124 million in 2007 to just $1.2 million in the first nine months of this year. The company's assets under management plummeted to $16.7 billion this fall, from $43 billion in 2007.

If shareholders approve the merger Tuesday, the always-multitasking Daniel Cohen will be in charge at just one publicly traded company.

Which raises the question: How long will that last?

Contact staff writer Harold Brubaker at 215-854-4651 or hbrubaker@phillynews.com.