Eurozone finance ministers moved Tuesday to boost the firepower of the debt rescue fund, agreeing to allow it to act as insurance to cover between 20-30 percent of potential losses incurred by government bond investors. "The final amount of 'firepower' achieved through the use of the options will depend upon the concrete use and mix of the instruments and particularly the exact degree of protection between 20 percent and 30 percent," the European Financial Stability Facility (EFSF) said in a statement.