MONTERREY, Mexico--(BUSINESS WIRE)--Fitch Ratings has maintained on Rating Watch Negative the 'BBB' and 'AAA(mex)' ratings assigned to the following Concesionaria Mexiquense, S.A. de C.V. (Conmex) debt issuances: --UDI1.6 billion notes due 2035; --UDI0.6 billion notional amount zero-coupon notes due 2046; --MX$6.5 billion Goldman Sachs loan due 2027. Fitch has also maintained the 'AAA(mex)' rating on the UDI1.5 billion notes placed in the local market in August 2014 on Rating Watch Negative. RA