Nippon Steel and U.S. Steel said Wednesday they have finalized their “historic partnership,” a year-and-a-half after the Japanese company first proposed its deal to buy the iconic American steelmaker for nearly $15 billion.

Japan-based Nippon Steel on Wednesday completed its buyout of U.S. Steel, changing its name to Nippon Steel North America, as the former U.S. industrial giant ended trading on Wall Street under its former brand name.

The agreement calls for Nippon Steel to invest roughly $11 billion across U.S. Steel’s domestic operations over the next three years, a move the companies say will protect and create more than 100,000 jobs.