Dalian Wanda Group, headed by China's richest man, said it has bought the organizer of Ironman Triathlon races for $650 million, in a diversification push that the property developer said may involve another sports purchase by year-end.

Wang Jianlin's Beijing-based Wanda bought World Triathlon Corp from U.S. fund Providence Equity Partners LLC for what the seller said amounted to $900 million including debt - in line with a Reuters exclusive report on the deal earlier in August.

The purchase is Wanda's latest sporting acquisition after Swiss marketer Infront Sports & Media and a stake in soccer club Atletico Madrid, as the group counters a slowdown in its domestic property market with a move into entertainment.

Wanda, parent of Dalian Wanda Commercial Properties Co, China's biggest commercial real estate developer, aims for revenue of $100 billion by 2020 from $40 billion in 2014. Ironman will bring in $183 million this year, following four years' compound growth of 21 percent, Providence said.

"Wanda's next task is to widely market this global extreme, endurance sport in China," Wang said at a briefing in Beijing. He said, without elaborating, that the group would likely buy another sports company before the end of the year.

Ironman comprises a 3.9 km (2.4 mile) swim, a 180 km bike ride and 42.2 km run, completed in under 17 hours. Wanda plans to hold as many as three races in China next year and increase Chinese participants to 200,000 over the next decade from 100.

Ironman Chief Executive Andrew Messick said Ironman hosts 200 events in 27 countries and has nearly 250,000 registered athletes.

"Wanda Group is a global-minded organization that shares our desire for excellence and continued growth, particularly in Asia," Messick said.

World Triathlon Corp's entire management has signed a long-term contract to continue following the acquisition, Wanda said.

Seller Providence will make a four-times return on its Ironman investment, said a person familiar with the matter who declined to be identified.