NEW YORK (Standard&Poor's) Nov. 15, 2002--Standard&Poor's Ratings Services said today that it had affirmed its 'BBB-' ratings on Banco Nacional de Comercio Exterior S.N.C.'s (Bancomext) senior unsecured long-term foreign currency debt, which is guaranteed by the United Mexican States (BBB-/Stable/A-3 foreign currency sovereign credit rating). "The rating reflects Bancomext's importance as the main government instrument to help promote international trade," said Sovereign analyst Sebastian Briozzo. "The bank assumes a primary role in the development of the external sector of the Mexican economy, providing funds to Mexican exporters and importers," he added. According to Mr. Briozzo, Bancomext recently began to redirect its role, strengthening its position as a provider of promotional activities and technical assistance to exporters