UNITED NATIONS, March 26 (Reuters) - A report by a special envoy for U.N. Secretary-General Ban Ki-moon recommended on Monday independence for Serbia's breakaway province of Kosovo, supervised by the international community. "Independence is the only viable option for a politically stable and economically viable Kosovo," special envoy Martti Ahtisaari said in a report to the U.N. Security Council. Ban said in a letter that he fully supported the recommendation. Ahtisaari, a former Finnish president, proposed that "the exercise of Kosovo's independence and its fulfillment of the obligations set forth in my settlement proposal, be supervised and supported for an initial period by international civilian and military presences."