A senior official at rating agency Standard & Poor's said on Wednesday that global markets have already discounted a possible U.S. ratings downgrade, and that Asian nations' ratings were generally on an uptrend despite global economic woes.

Market is to some extent already discounted to the potential risk of a U.S. downgrade, Takahira Ogawa, director of sovereign ratings at S&P, told Reuters.

He said Indonesia, the Philippines and South Korea have a relatively larger proportion of debt held by foreign funds and could be more vulnerable to any risk aversion, but said most Asian sovereign ratings were on the uptrend.

However, he said Japan's finances remained a worry.

We see Japan sovereign risk still increasing but not to the extent for us to have another action, Ogawa said.

(Reporting by Raju Gopalakrishnan and Kevin Lim)