Venezuela's President Hugo Chavez (C) acknowledges supporters before the registration of his presidential bid to the electoral authorities in Caracas June 11, 2012. Chavez formally registers his candidacy for the October 7 election as rumours continue over the state of his health. [Photo/Agencies]

Venezuela's President Hugo Chavez waves to supporters before the registration of his presidential bid to the electoral authorities in Caracas June 11, 2012. Chavez led his biggest rally since he was diagnosed with cancer a year ago, seeking to stage a show of strength on Monday as he heads into a re-election campaign to extend his 13 years of socialist rule.[Photo/Agencies]