LUANDA (Reuters) - Angola's foreign minister shrugged off a downgrade by Fitch Ratings on Saturday and said authorities had taken the right steps to shield the oil-dependent economy from falling crude prices. The ratings agency cut Angola's credit rating to B+ from BB- with a stable outlook on Friday, saying the nation's heavy reliance on revenues from oil exports left it exposed to sharp price decreases. "I'm not worried about the downward revision by Fitch, because the medium-term economic outlook is stable," Foreign Minister Georges Chikoti told Reuters on Saturday. "Angola has already reacted well to oil dependence and the devaluation of the national currency," he added. The central bank has repeatedly devalued Angola's kwanza currency in a bid to bolster foreign exchange reserves in Africa's second-biggest oil exporter. Earlier this month, the finance minister said the country needed to cut spending to match falling oil sales revenue. Oil output represents about 40 percent of Angola's gross domestic product (GDP) and more than 95 percent of export revenue. Global oil prices have been dragged lower by a supply glut driven by record pumping by members of the Organization of the Petroleum Exporting Countries (OPEC) as well as weak demand from China.