Fort Wayne industrialist Keith Busse said a previous commitment will prevent him from joining Republican presidential candidate Mitt Romney at a campaign stop in Chicago next week.

Romney invited Busse, chairman and a founder of Steel Dynamics Inc., in a text message, Busse confirmed Friday.

Busse said his own commitment Monday "involves a charity, and I'm going to honor that."

Romney has touted Steel Dynamics as a thriving company that he helped get off the ground in the 1990s as the leader of Bain Capital, a Boston-based private equity firm. When he accepted his party's nomination at the recent Republican National Convention in Tampa, Fla., Romney noted that Steel Dynamics has become "one of the largest steel producers in the United States."

Asked whether he might campaign with Romney this fall, Busse said: "I suppose if he's in Indiana and I have free time, I'd love to join him. But I have no specific plans."