Fitch Ratings said Tuesday it has upgraded its ratings on Nippon Steel Corp. and JFE Holdings Inc., the country's top two steel manufacturers, because of their improved financial standing and strong business performance.

Nippon Steel's rating on its senior unsecured debt denominated in yen and foreign currencies was raised to BBB plus from BBB, and that for JFE was raised to BBB from BB plus. The Nippon Steel rating on short-term debt was upgraded to F2 from F3 and that for JFE from B to F3. The outlook is stable for both companies, Fitch said.