Cleveland Cliffs wants more information on who the other potential buyers are for U.S. Steel.
The Ohio-based steelmaker made a more than $7 billion offer to buyout U.S. Steel earlier this month.
In a recent letter from their CEO, Cleveland Cliffs argues they have the right to know about the potential buyers through the United Steelworkers—the Pittsburgh union that represents thousands of workers at both companies.
U.S. Steel initially rejected Cleveland Cliffs first offer, with the company saying it was going to take time to weigh their options.
There has been no update on possible moves by U.S. Steel since the proposal was made.
