Peace researchers dropped Colombia on Monday from a list of favorites for the Nobel Peace Prize after Colombians voted "No" in a referendum to an agreement to end a 52-year war with Marxist rebels.Sunday's surprise rejection of the accord improved chances for other Nobel candidates such as Russian human rights activists or brokers of Iran's nuclear deal to take the peace award, they said."Colombia's off any credible list," Kristian Berg Harpviken, head of the Peace Research Institute, Oslo, speaking to reporters about the 2016 Nobel Peace Prize that will be announced in Oslo on Friday at 0900 GMT.President Juan Manuel Santos and FARC's top commander Rodrigo Londono, better known by his nom de guerre Timochenko, had been widely tipped for the 8.0 million Swedish crown ($936,000) award before the referendum.