SAN FRANCISCO (MarketWatch) -- Moody's Investors Service on Monday lowered France's sovereign rating by one notch to Aa1, stripping the country of its coveted triple-A rating. "France's long-term economic growth outlook is negatively affected by multiple structural challenges, including its gradual, sustained loss of competitiveness and the long-standing rigidities of its labor, goods and service markets," said Moody's in a statement. The ratings agency also expressed concern over France's uncertain fiscal outlook and noted that its resilience to future euro-shock is becoming more difficult to predict. The rating outlook remains negative.