Cliffs would purchase all of U.S. Steel for all cash and then sell off the Big River Steel subsidiary to Nucor, sources told CNBC's David Faber. U.S. Steel's headquarters would remain in Pittsburgh under the deal.

KEY TAKEAWAYS U.S. Steel shares jumped Monday on a report that Cleveland-Cliffs is teaming up with rival Nucor for a potential bid for the company.The news comes after Nippon Steel's $14.1 billion takeover of U.

Joint bid for U.S. Steel assets would have Cleveland-Cliffs acquiring blast furnace mills and Nucor taking over Big River Steel, according to CNBC and Bloomberg.