Questions have been asked about profitable companies buying shell companies with a large tax loss on their books to be used to offset their gains. Basically, this cannot be done.

Breifly - years ago, profitable companies were buying shell companies with large NOLs (Net Operating Loss) to be used to offset their taxable income. But in 1986, Congress ended this tax shelter by enacting rules that limited using the NOL when there was an ownership change of greater than 50% within three years.

Following are some article on the subject:
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1.382-2T(a)(1) of the Income Tax Regulations.

"Section 382 of the tax code was created by Congress in 1986 to end what it considered an abuse of the tax system: companies sheltering their profits from taxation by acquiring shell companies whose only real value was the losses on their books. The firms would then use the acquired company's losses to offset their gains and avoid paying taxes."
http://www.washingtonpost.com/wp-dyn/content/article/2008/11/09/AR2008110902155_pf.html

"Generally, an ownership change occurs when, within a span of 36 months (or, if shorter, the period beginning the day after the most recent ownership change), there is an increase in the stock ownership by one or more shareholders of more than 50 percentage points. For example, if Shareholder A owned 25 percent of Corporation X, and within a space of three years, acquired another 51 percent, there would be an ownership change, triggering section 382."
http://www.pmstax.com/acqbasic/sec382.shtml

Section 382
http://www.taxalmanac.org/index.php/Sec._382._Limitation_on_net_operating_loss_carryforwards_and_certain_built-in_losses_following_ownership_change

Guidance to corporations whose instruments are acquired by the Treasury Department
http://www.treasury.gov/initiatives/eesa/docs/Notice%202008-100.pdf

Paper on the subject:
http://bednarski.us/irsNotice2008-83-final.pdf