(Reuters) -U.S. Steel has entered into confidentiality agreements with "numerous third parties" and started to review multiple unsolicited proposals ranging from partial acquisition to an entire buyout, the company said in a letter to its stockholders on Tuesday.
Chairman David Sutherland and CEO David Burritt said in the letter that the company will start to share due diligence information.
They also said the company's board and outside advisers will fully evaluate all options and make the review public to hear from any party that may have interest in the company.
Cleveland-Cliffs (NYSE:CLF), which has made a $7.3 billion cash-and-stock offer, last week demanded U.S. Steel to provide the company and the United Steel Workers (USW) union with information about all the proposals it has received so far as a part of its strategic review.
Shares of U.S. Steel ended 3.2% higher at $30.87 on Tuesday.
Earlier this month, Esmark scraped its bid for U.S. Steel, leaving Arcelor-Mittal as the only known potential challenger to Cleveland-Cliffs.
"While we don’t know how long the process will take, the board of directors, management team and outside advisers are moving quickly to complete it," U.S. Steel said in the letter.