...Fitch Ratings has downgraded Grupo Famsa S.A.B. de C.V.'s (Famsa) Local and Foreign Currency Long-Term Issuer Default Rating (IDR) to `B' from `B' as well as the long-term National Scale rating to `BB(mex)' from `BBB(mex)'. The Rating Outlook is Stable. In addition, Fitch has downgraded Famsa's National short-term rating to `B(mex)' from `F3(mex)'. The rating downgrades reflect the company's high leverage, constant capital requirements from its subsidiary Banco Ahorro Famsa (BAF), the deterioration of Famsa's U.S. operations and the expected economic slowdown in Mexico, which will pressure the company's cash flow generation in 2017. Famsa's expected improvements in operating margins will not be sufficient to offset the company's current challenges....