NEW YORK (

TheStreet

) --

Ambac Financial Group

(ABK)

has withdrawn plans filed more than a year ago for the sale of up to $1 billion worth of securities.

The New York City-based company, whose mortgage bond insurance business remains hamstrung from the financial crisis, said in a filing with the

Securities and Exchange Commission

after Thursday's closing bell that it was withdrawing the S-3 registration statement it filed on April 1, 2009 because it has been unable to meet a deadline to file its 10-K for fiscal 2009, rendering it ineligible to issue securities.

Ambac shares finished Thursday's session down 5 cents, or 8.5%, at 49 cents on volume of 7.6 million, less than half the issue's trailing three-month daily average of 17.8 million. The volatile stock is down more than 50% since the start of 2010, but it was trading above $1 as recently as July 27.

The company has been the subject of speculation about a possible filing for bankruptcy protection for months, and it first raised the

possibility of pursuing a prepackaged bankruptcy plan

when it filed ts 10-Q for the third quarter of fiscal 2009 back in November of last year.

An Ambac spokesperson wasn't immediately available for comment.

--

Written by Michael Baron in New York.

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