ATHENS, Greece — Greece’s finance minister and international debt inspectors ended a conference call Monday night without a decision on whether the inspectors will return to Athens, a vital point that could affect whether the nation gets more bailout funds or defaults on its debts. As global stocks fell on fears of a Greek default, Athens struggled to convince officials from the European Commission, the European Central Bank and the International Monetary Fund that the country could meet strict budget targets promised in return for the international cash lifeline.