MEXICO CITY (Reuters) -The U.S. government said on Friday it did not plan to renew the antitrust immunity that Delta Air Lines and Aeromexico currently operate a codeshare agreement under, after the Mexican government made sweeping changes at the country's main capital airport. Last year, Mexican officials moved cargo flights from Mexico City International Airport (AICM), the country's busiest airport, to a newer airport ordered built by the president on the outskirts of town.