VINA DEL MAR, Chile, July 3 (Reuters) - Mexico's investment-grade ratings should be maintained and there is no reason for them to be changed by credit rating agencies, the country's finance minister said on Friday.

Agustin Carstens, speaking at a meeting of finance ministers from the Americas, rejected the view of some analysts who have said the country could be downgraded absent key fiscal reforms. (Editing by James Dalgleish)