New Delhi, Sept. 29 -- A potential initial public offering (IPO) of Tata Sons is unlikely to have any immediate impact on the credit ratings of Tata group companies, but a change in the holding company's ownership structure could influence how S&P Global Ratings assesses group support over the longer term, the ratings agency said.

In a bulletin issued on Tuesday, S&P Global said changes in the Tata group's financial policies are likely to be gradual.

It said, "Any changes in the Tata group's financial policies are likely to be gradual. A potential listing of holding company Tata Sons and leadership transition at the group would therefore have no immediate impact on our ratings on group entities".

S&P currently rates Tata Steel Ltd., Ta...