NEW YORK (REUTERS) - China's President Xi Jinping personally decided to pull the plug on Ant Group's US$37 billion (S$50 billion) initial public offering, the Wall Street Journal reported on Thursday (Nov 12), citing Chinese officials with the knowledge of the matter.

The decision to stop what would have been the world's largest ever IPO, came days after the fintech giant's billionaire founder Jack Ma launched a public attack on the country's financial watchdogs and banks.

President Xi ordered Chinese regulators to investigate and effectively shut down Ant's stock market flotation, the report said.

Ant Group did not immediately respond to Reuters request for comment.

The Information Office of the State Council, China's Cabinet, could not be reached immediately for comment.

Mr Ma had told a summit in Shanghai on Oct 24 that the regulatory system was stifling innovation and must be reformed to fuel growth.

Earlier this month, Reuters reported the speech set off a chain of events that torpedoed the listing of Ant.

Soon after Mr Ma's scathing speech, state regulators started compiling reports including one on how Ant had used digital financial products like Huabei, a virtual credit card service, to encourage poor and young people to build up debt.

The general office of the State Council compiled a report on public sentiment about Mr Ma's speech and submitted it to senior leaders including President Xi, Reuters had reported.