(AGI) Buenos Aires, July 2 - Argentina is being kept underobservation because of a risk of defaulting, said internationalrating agency Standard & Poor's. The country has a long-term"CCC" rating but there is concern over debt interest payments.The agency said a U.S. court ruling blocked a 539 billiondollar payment of bond holders' interest. They accepted a shareswap, due to a legal dispute over hedge funds which BuenosAires calls "vulture funds". . .