By Jack Kim

SEOUL (Reuters) - Sun Myung Moon, the founder and head of the Unification Church which has millions of followers around the world, died at a retreat near the South Korean capital Seoul on Monday, church officials said.

Moon was 92 and had suffered complications from pneumonia, the officials said. Moon had been hospitalized in Seoul in mid-August and was moved to the retreat last week when his family and church believed there was little chance of recovery.

Moon had led an active public life until recently, officiating a mass wedding for 2,500 in March and leading a service of more than 15,000 followers in July.

The church said he had fallen gravely ill in early August after a lingering bout of cold and exhaustion that began in July.

Moon is survived by his wife - the pair are called "true parents" by followers - and 10 of their 13 children.

Born in what is now North Korea in 1920, Moon founded the church soon after the Korean War that ended in 1953, rapidly expanding the ministry internationally and building a business at the same time that served as the backbone of the empire.

The Unification Church runs the Segye Times newspaper in South Korea and more than a dozen other firms in South Korea along with overseas businesses.

Critics of the church have for years vilified the organization as a heretical and dangerous cult and questioned its murky finances and how it indoctrinates followers, described in derogatory terms as "Moonies."

Moon has handed over day-to-day operations of the church, which has its headquarters in Seoul, to one of his sons and the management of the Tongil Group with interests in construction, resorts, travel agencies and a newspaper to another son.

Moon, whose group runs the conservative Washington Times publication and is known as a strident anti-communist, visited North Korea in 1991 and met the reclusive state's founder Kim Il-sung to discuss business ventures and unification.

South Korea, which remains technically at war with the North, criticized the visit.

(Additional reporting by Sung-won Shim; Editing by Jon Hemming)