...Stand-Alone Strength: Banco Internacional del Peru S.A.'s (Interbank) Long-Term Issuer Default Rating (IDR) is based on its stand-alone financial strength, as reflected in its Viability Rating (VR). Strong Retail Banking Franchise: Interbank is the fourth-largest universal commercial bank in Peru, with a financial system market share of 10% at YE17 and outsized strength in retail banking. Interbank's market share in personal loans and credit cards was 23.5% and 19.4%, respectively, at YE17. Consistent Profitability: Interbank's profitability modestly softened for the second consecutive year in 2017 but continued to compare well with the private bank average. Operating profit declined to 3.0% of risk-weighted assets (RWA) from 3.1% in 2016. The bank's net interest margin declined to 7.6% from 7.9% on average interest-bearing liabilities, responding to an increase in funding costs, negative growth in the credit card portfolio and high competition in corporate banking. Increased impairment...