The company made the filing with the U.S. Securities and Exchange Commission for the listing, which could happen in the first half of this year, the sources said.

The IPO could raise between $300 million and $500 million, the people said, though one cautioned that $500 million might be high.

A Wanda spokesman did not provide any immediate comment.

Wanda's sprawling business empire ranges from real estate to sport to cinemas, but it has been rattled in the past years by a government-led crackdown on overseas deals and high leverage.

The company owned by Wang Jianlin, one of China's richest men, has since started offloading domestic and overseas holdings, including stakes in cinema operator AMC Entertainment and Spanish soccer club Atletico Madrid and a handful of property developments.

Other Chinese conglomerates such as HNA group and Fosun International have also faced government pressure to cut down on what Beijing has termed irrational overseas deals.

An IPO of Wanda's sports assets would include Infront Sports & Media AG, a Swiss sports marketing company and World Triathlon Corp, the organizer and promoter of the Ironman race, three sources previously told Reuters.

The two were acquired in 2015 for $1.2 billion and $650 million respectively. Wanda, while preparing the IPO, had also received offers for the businesses from a number of private equity firms, Reuters reported.

Citigroup, Deutsche Bank and Morgan Stanley are working on the deal, the sources said. Citigroup and Deutsche Bank declined to comment. Morgan Stanley did not immediately respond to a request for comment.

Chinese companies have dominated the ranks of those looking to go public worldwide, raising $58.2 billion in IPOs last year, accounting for 29 percent of global issuers, according to Refinitiv data.

They have also been very active in U.S. listings, raising $9.1 billion last year, the highest level since 2014, Refinitiv data showed.

(Reporting by Kane Wu, Julia Fioretti and Julie Zhu in HONG KONG and Joshua Franklin in NEW YORK; writing by Julia Fioretti; Editing by Simon Cameron-Moore)