US Steel has knocked back a $7.3 billion bid approach from Cleveland-Cliffs, North America's leading flat-rolled steel producer.
The proposed deal, a combination of shares and cash, was set at $35 per share, marking a 43% premium on US Steel's Friday closing price of $22.72.
Despite the rejection, Cleveland-Cliffs CEO Lourenco Goncalves is still hoping to broker a deal.
If successful, the merger would establish the sole US steel firm ranked among the world's top 10 producers.
Acquisitive Cleveland-Cliffs purchased ArcelorMittal's US steelmaking assets for $1.4 billion in 2020 and acquired AK Steel for $1.1 billion in 2019.
The United Steelworkers union has shown support for Cleveland-Cliffs' bid to acquire US Steel, stating it would not back any other contender.
Historically, Pittsburgh-based US Steel has been emblematic of US manufacturing since its inception in 1901.
However, the company has faced challenges recently, with its stock price declining by 24% over the past five years, in contrast to Cleveland-Cliffs' 42% rise.