MEXICO CITY, June 18 (Reuters) - The Commission for

Environmental Cooperation (CEC), which oversees environmental

issues in the United States, Mexico and Canada, on Thursday said

it will review a complaint alleging Mexico failed to enforce

environmental laws following hydrocarbon contamination caused by

an incident at an oil well in Las Choapas, in the state of

Veracruz.

* An incident in early March led to a loss of operational

control at Pemex's Krem 1EXP exploratory well, the

complaint, first issued on June 9, says.

* Prolonged emission of gas from the well is ongoing, the

complaint says, and the discharge of related waste is

contaminating waterways, generating acid rain, harming crops and

livestock, and exposing nearby communities to environmental and

health risks.

* Work to extinguish and contain the emissions is expected

to take about two weeks, the director of Mexico's state-run oil

firm Pemex said on June 5, with the incident reportedly under

control and supplies mobilized to address the issue.

* Pemex said in a June 12 statement that air quality tests

showed pollutant concentrations were within permissible limits

and that while there are no settlements near the site, it is

providing mobile medical services to residents of the Las

Choapas municipality.

* The CEC has 30 days to decide whether Mexico should

respond to the complaint.

(Reporting by Leon Ramirez, Editing by Iñigo Alexander)