Much of Ex-Im Bank’s activity is under so-called bundling facilities. A bundling facility is a large medium-term loan made to a Mexican bank by a U.S. bank with the guarantee of Ex-Im Bank. The Mexican bank then makes loans to Mexican companies for the purchase of American capital goods. There also are a number of U.S.-based banks that extend Ex-Im Bank credits in Mexico. The major Mexican commercial banks have signed agreements with Ex-Im Bank to grant lines of credit to Mexican firms that purchase U.S.-made products. Many major Mexican banks (Santander, BBVA-Bancomer, and others) have Master Guarantee Agreements. Such credits generally are available only to Mexican blue chip companies and to their suppliers with firm contracts