June 7 (Reuters) - Rating agency Moody's Investors Service said on Monday that China's new policy allowing couples to have up to three children could support fertility, but was unlikely to dramatically change the national birthrate.

The rating agency said that the policy highlighted the risk of aging across emerging markets in Asia.

"And although China's new policy allowing couples to have up to three children could support fertility, it is unlikely to dramatically change the national birthrate, meaning that aging will remain a credit-negative constraint", Moody's said in a statement.

(Reporting by Kanishka Singh in Bengaluru; Editing by Christian Schmollinger)