Plant owner Mittal Steel Co. NV of the Netherlands and steel maker Esmark Inc. of Chicago Heights, Ill., worked past a self-imposed midnight deadline for saving the deal they announced in early August, Mittal spokesman William Steers said.

Esmark is the lead partner in E2 Acquisition Corp., an international investment group that was selected from among a number of bidders for the plant Mittal must sell to resolve federal antitrust issues.

"We continue to work with all parties involved, including E2 Acquisition Corporation, the union and the Department of Justice, to bring a successful conclusion to this process," Steers said in an e-mailed statement.

Financing for the transaction was thrown into doubt Nov. 30, when Esmark's agreements with its international partners lapsed due to delays. Esmark President Craig T. Bouchard, who heads E2, said last week that the investors remained committed to the deal but indicated new partners might be added.

The original partners were Franklin Templeton Investments of San Mateo, Calif.; Industrial Union of Donbass Corp., a Ukrainian steel company; and Vale, a Brazilian mining company previously called Companhia Vale do Rio Doce, or CVRD.

Bouchard blamed the delays on the lack of an agreement between Mittal and the United Steelworkers union covering benefits for the plant's 84,000 retirees -- an obligation Bouchard said Mittal inherited when it bought Sparrows Point in 2005.

But Mittal spokesman William Steers said Monday that those discussions were not preventing Mittal from closing on the deal.

Failure to finalize the deal could prompt court-appointed trustee Joseph G. Krauss to seek another buyer for the mill, Krauss said Monday.

Mittal agreed to sell Sparrows Point to E2 to resolve antitrust concerns raised by the U.S. Justice Department stemming from Mittal's planned $41 billion acquisition of Arcelor SA of Luxembourg, which would create the world's largest steelmaker, ArcelorMittal.