MEXICO CITY (AP) — Mexico's president is celebrating the resignation of the longtime head of the country's oil workers union, who ruled the syndicate for nearly three decades with an iron fist before quitting following repeated scandals over alleged corruption.

Andrés Manuel López Obrador says the departure of Carlos Romero Deschamps marks "the beginning of a new stage" and that there must be free and democratic governance of unions with "transparency in the management of funds from worker dues."

He adds that corruption must not be allowed.

Also Thursday, Deschamps released a public letter in which he defended his 26-year leadership of the Union of Oil Workers of the Mexican Republic. He touted achievements on things like pensions, health care and worker housing, and surviving massive budget cuts without any layoffs.