MONTERREY, Mexico--(BUSINESS WIRE)--Fitch Ratings has placed the following two toll road transactions sponsored by OHL Mexico on Rating Watch Negative: Concesionaria Mexiquense (Conmex) and Grupo Autopistas Nacionales (Gana). The affected debt issuances are: Conmex's debt: --UDI1.6 billion notes due 2035 rated 'BBB' and 'AAA(mex)'; --UDI0.6 billion zero-coupon notes due 2046 rated 'BBB' and 'AAA(mex)'; --MXN6.5 billion Goldman Sachs loan due 2027 rated 'BBB' and 'AAA(mex)'; --UDI1.5 billion loc