* Lists assets of $70 mln and liabilities of $1.07 bln as of Dec. 31
* Noteholders to receive 79 pct of stock in reorganized company
* Shares fall 46 pct before the bell
March 5 (Reuters) - USEC Inc filed for bankruptcy after struggling with weak prices for the enriched uranium it supplies to nuclear power plants and difficulties in financing a major project.
Shares of the company, which said in December it expected to file for bankruptcy protection, fell as much as 46 percent to $3.01 in premarket trading on Wednesday.
Prices for low-enriched uranium have plummeted more than 30 percent since March 2011, when a tsunami crippled the Fukushima nuclear power plant in Japan.
Demand for nuclear fuel remains weak, with more than 50 reactors going off line in Japan and Germany since the tsunami.
Tokyo Electric Power Co, the operator of the Fukushima nuclear plant, has historically been one of USEC's largest customers, according to regulatory filings.
USEC, which also counts Exelon Corp and Entergy Corp among its customers, said it expects to emerge from bankruptcy protection in 90 to 120 days.
Besides weak demand, USEC has also been hit by delays in securing funding for its American Centrifuge Project in Ohio.
The company was banking on production from the project after it ceased enriching uranium at two gaseous diffusion plants leased from the Department of Energy (DOE).
USEC has spent about $2.5 billion to develop the plant and needs more than $4 billion to complete it, the company said in its bankruptcy filing.
The company sought a $2 billion loan guarantee from the DOE, but the government proposed a cost-sharing program to demonstrate the capability of the centrifuge technology.
The $350 million research and development program, 80 percent funded by DOE, has been extended through April 15.
USEC said it would continue to supply its customers from stockpile.
USEC's plan of reorganization, backed by those holding about 65 percent of the company's debt and investors Toshiba Corp and Babcock & Wilcox Investment Co, will replace USEC's debt and stock with a new debt issue totaling $240.4 million and new stock.
Noteholders will get $200 million of new debt and a 79 percent stake in the reorganized company.
Toshiba and Babcock & Wilcox Investment will each receive $20.19 million of new debt and 8 percent of the new shares.
Babcock & Wilcox Investment is a unit of power generation systems maker Babcock & Wilcox Co.
Existing USEC stockholders will receive 5 percent of the new shares. The company's proposed reorganization plan requires court approval.
USEC listed assets of $70 million and liabilities of $1.07 billion as of Dec. 31.
The Bethesda, Maryland-based company has 505 employees.
USEC's legal advisor for the restructuring is Latham & Watkins LLP, its financial advisor is Lazard, and its restructuring advisor is Alix Partners LLP.
The case In re: USEC Inc, No.14-10475, U.S. Bankruptcy Court, District of Delaware.