Thyssenkrupp, the German steel giant, gave a muted welcome to Standard & Poor's decision to restore its investment grade rating two years after cutting it to junk because of an underfunded pension scheme.

The firm said in a statement: "Thyssenkrupp welcomes S&P's rating action and has thus been returned to investment grade status by S&P. The ratings from Moody's and Fitch have remained in the investment grade area since they were first issued."