US Steel Warns Thousands Jobs at Risk Without Nippon Steel (2)

United States Steel Corp. is warning union leaders and politicians pushing to block its $14.1 billion acquisition by Nippon Steel Corp. that doing so would imperil thousands of jobs and its Pittsburgh headquarters.

Without the Japanese steelmaker’s support, US Steel would have to pivot away from its legacy blast furnaces, endangering union jobs and undermining the competitiveness of the American steel industry, the company said in a statement Wednesday. The warning echoes comments by Chief Executive Officer David Burritt to the Wall Street Journal.

Shares of US Steel rose as much as 4.1% Wednesday in New York in …