LONDON (AP) -- The IOC called for unity among the world's national Olympic committees Friday following the internal political conflict that led to the abrupt resignation of longtime Olympic powerbroker Mario Vazquez Rana.
The 79-year-old Mexican media magnate resigned Thursday as president of the Association of National Olympic Committees, a position he held for more than 30 years.
Vazquez Rana also quit his roles as International Olympic Committee member, IOC executive board member and president of Olympic Solidarity, the body that distributes grants to national bodies to help athletes from smaller nations to compete at the games.
In a four-page resignation letter, Vazquez Rana angrily denounced an "outrageous and aggressive" campaign by his opponents to oust him ahead of ANOC's assembly in Moscow next month, underscoring the infighting that has dogged his leadership in recent months.
Vazquez Rana, who turns 80 in June, was required by IOC age rules to give up his executive board seat in July and his 21-year membership at the end of the year.
He unsuccessfully sought to extend those terms, and then came under pressure to relinquish the ANOC post. ANOC represents the world's 204 national Olympic bodies.
"The IOC would like to thank Mr. Vazquez Rana for his great merits and contribution to the Olympic Movement for over 30 years," the IOC said in a statement to The Associated Press.
"The IOC hopes that the upcoming ANOC General Assembly in Moscow next month will bring a message of unity and concord for the sake of the athletes who will compete in London this summer," the statement said.
Vazquez Rana, who remains chairman of the Pan American Sports Organization, called his resignation from the other posts a "drastic decision."
The Mexican had headed ANOC since 1979 and used the position to establish himself as one of the most powerful figures in the Olympic movement. He made enemies along the way, with critics accusing him of being autocratic.
Vazquez Rana was re-elected to another four-year term as ANOC president in 2010. But with his IOC membership coming to an end this year, opponents have been pushing him to leave now and allow younger leaders to take over.
Vazquez Rana faced a possible revolt at the ANOC meeting in Moscow, when some delegates were expected to seek his ouster. A number of delegates have been meeting in Thailand this week to discuss strategy.
In his letter, Vazquez Rana accused his opponents of disloyalty and "shady alliances and questionable procedures."
IOC member Patrick Hickey of Ireland is in line to take Vazquez Rana's place on the executive board, with Sheikh Ahmad Al-Fahah Al-Sabah of Kuwait poised for the ANOC presidency. Both are ANOC vice presidents.
Vazquez Rana angered some sports leaders last week in Mexico City, where he refused requests for a secret ballot so he could be re-elected by applause and acclamation to another four-year term as PASO chief. He did not attend the IOC executive board meetings in Lausanne, Switzerland, this week.