By Alister Doyle and Jessica Jaganathan
OSLO (Reuters) - A Colombian peace accord ending a half-century of war is widely tipped for the Nobel Peace Prize next week, returning the award to its roots after a run of wins for organizations including the European Union.
The prize might be shared by President Juan Manuel Santos and Marxist FARC rebel leader Timochenko - the nom de guerre of Rodrigo Londono - after they signed a deal on Sept. 26 to end a war that killed a quarter of a million people.
"The agreement ... is one of the most obvious peace prize candidates I've ever seen," said Asle Sveen, a historian who tracks the awards. Still, he said a prize may hinge on a "Yes" to the agreement in a referendum in Colombia on Sunday.
It would be the first award for Latin America since Guatemalan human rights activist Rigoberta Menchu won in 1992.
Other candidates for the 8.0 million Swedish crown ($934,000) prize include Svetlana Gannushkina, a Russia campaigner for human rights and refugees, Syria's White Helmets, a civilian group that seeks to rescue victims of air strikes, or Greek islanders who have aided Syrian refugees.
Others tips include negotiators of a deal over Iran's nuclear program or former U.S. spy contractor Edward Snowden who leaked details of U.S. surveillance.
Kristian Berg Harpviken, head of the Peace Research Institute, Oslo, puts Gannushkina as his favorite, with Colombia second, saying such a prize would be an overdue rebuke to President Vladimir Putin.
"Ten years into the future there's a risk that it will be seen as major omission by the Nobel Committee," he said of a lack of criticisms of Russian restrictions on human rights and the annexation of Ukraine's Crimea region in 2014.
An award for Colombia would shift the prize back to traditions of peace-making by individuals. The five-strong Nobel committee, comprising several former politicians, might also be swayed because Norway helped broker the accord.
Organizations have won three of the past four years in the strongest run since the awards were set up in the 1895 will of Sweden's Alfred Nobel, a philanthropist and inventor of dynamite.
Last year's prize went to Tunisia's National Dialogue Quartet, for peacefully helping build democracy, in 2013 to the Organization for the Prohibition of Chemical Weapons and in 2012 to the European Union, now set to shrink after Britain voted to leave.
"There was less interest in the media when there was only an organization," said Geir Lundestad, who was secretary to the secretive committee from 1990-2014.
In many years, prizes to organizations have been shared with a person to give a human face, such as when the United Nations won with Secretary-General Kofi Annan in 2001.
Before the EU, the last prize solely to an organization was in 1999, to Medecins sans Frontieres. Harpviken said there was no suggestion the prize was losing luster - there were a record 376 nominees this year.
Thousands of people, including all members of national parliaments worldwide, university professors of subjects such as history and law and former winners can make nominations.
Individuals have always been the most compelling winners.
This year's award comes days after the death of Israel's Shimon Peres, who shared the 1994 prize with late Prime Minister Yitzhak Rabin and Palestinian leader Yasser Arafat. Mother Teresa, the 1979 winner, was declared a saint by Pope Francis this month.
The prizes begin on Oct. 3 with Physiology or Medicine, Physics on Oct. 4, Chemistry on Oct. 5, Peace on Oct. 7, Economics on Oct. 10. The date of the Literature Prize has not yet been set. All except peace are awarded in Stockholm.
Japanese write Haruki Murakami, Syrian poet Adunis and U.S. novelist Philip Roth are among favorites for the hard-to-predict literature award, according to bookmakers Ladbrokes.
Among the favorites for Physics are scientists who detected gravitational waves, ripples in space and time hypothesized by Albert Einstein a century ago, according to a study by the Intellectual Property and Science business of Thomson Reuters.
(Reporting by Alister Doyle; Editing by Alison Williams)