(Corrects paragraph 9 to show Enkhbayar helped negotiate the Oyu Tolgoi investment agreement but did not sign it)
ULAANBAATAR, May 15 (Reuters) - Mongolia's controversial former president, Nambar Enkhbayar, will not be allowed to stand in presidential elections next month because of registration irregularities and his conviction for graft in 2012, the election commission said.
Enkhbayar, one of the country's most popular politicians, was picked to contest the June 26 vote by the Mongolian People's Revolutionary Party (MPRP), but the election panel said on its official website on Sunday his registration had been refused.
A spokesman for the MPRP could not immediately be reached for comment.
Mongolia, a former Soviet satellite sandwiched between China and Russia, is regarded as an oasis of democracy in the region, and goes to the polls next month to choose a new head of state after incumbent Tsakhia Elbegdorj completes his second term.
But voters have grown increasingly frustrated with elected officials amid growing wealth disparities, a collapse in foreign investment and an economic crisis that has forced the government to turn to the International Monetary Fund for assistance.
Enkhbayar's exclusion now leaves the way clear for the ruling Mongolian People's Party (MPP) candidate, Miyeegombo Enkhbold, and a martial arts star turned business tycoon, Khaltmaa Battulga, of the opposition Democratic Party.
Enkhbayar was jailed in 2012 over a conviction for profiting from illegal privatisations. He and his supporters insist the conviction was politically motivated and he was pardoned in 2013, weeks after Elbegdorj's second-term election victory.
The terms of the pardon forbade him from holding political office until the end of his original sentence on October 8 this year.
Enkhbayar was prime minister from 2000 to 2004 and then president from 2005 to 2009, when he helped negotiate a landmark investment pact for the Oyu Tolgoi copper-gold mine with Ivanhoe Mines, now known as Turquoise Hill Resources and controlled by Rio Tinto.
He formed the MPRP in 2010 as a break-away movement after falling out with leaders of the MPP who sought to distance themselves from the party's socialist roots. The MPRP is the original name of the party that ruled Mongolia for decades as a one-party state under Soviet backing. (Reporting by Terrence Edwards; Editing by David Stanway and Clarence Fernandez)