Mexican Sen. Manlio Fabio Beltrones says he won't seek the presidential nomination for the Institutional Revolutionary Party, leaving former Mexico State Gov. Enrique Pena Nieto effectively unopposed.
Beltrones says in an announcement published Tuesday that he wants to maintain his party's unity as it seeks to regain the presidency it lost in 2000 after 71 years in power.
The move means that two of the three major candidates expected to compete in the 2012 race are unofficially set.
Andres Manuel Lopez Obrador of leftist Democratic Revolution Party was selected as presidential nominee after winning an opinion poll released last week.
President Felipe Calderon's National Action Party has yet to choose a candidate.