"The waiting period under the Hart-Scott-Rodino Antitrust Improvements Act (HSR) terminated on January 29, 2014 with respect to its acquisition, through a 50/50 joint venture with Nippon Steel & Sumitomo Metal Corporation, of ThyssenKrupp Steel USA," ArcelorMittal said in a statement.
The termination of the HSR waiting period satisfies one of the conditions to the closing of the acquisition, it said.
"Subject to the satisfaction of other customary conditions (including the receipt of additional regulatory approvals), the acquisition is expected to close later in the first quarter of 2014 or in the second quarter of 2014," it added.
ArcelorMittal, Nippon Steel & Sumitomo Metal Corporation have formed a joint venture and will finance the deal through equity and debt.
Last month, ArcelorMittal Chairman and CEO Lakshmi N Mittal had said the acquisition of ThyssenKrupp AG's (TKAG) steel mill in the United States for USD 1.5 billion would help the firm to cash in on the growing demand for auto-grade steel in North American Free Trade Agreement (NAFTA) region.
The plant at Calvert, Alabama, has a capacity of 5.3 mtpa. Thyssenkrupp is Germany's largest steel maker.
ArcelorMittal is the world's leading steel and mining company with presence in more than 60 countries.