According to the newspaper, the international union and five of its locals have filed grievances over the acquisition, contending that company did not share information about the sale process, and that the union “hadn’t been consulted nor reassured that its collective bargaining agreements would be honored,” the newspaper said. 

U. S. Steel told the newspaper that it has met its obligations under the basic labor agreement and is looking to quickly and favorably resolve the grievances. The company has said it hopes to finalize the acquisition in the second or third quarters of this year. 

You can read more here.