London CNN Business  — 

Ant Group’s highly anticipated IPO has been suspended following a meeting between the company’s billionaire co-founder Jack Ma and regulators in China, an abrupt move that threatens what was due to be the largest share sale in history.

The Shanghai Stock Exchange said in a statement on Tuesday that it had postponed the company’s listing, less than two days before its shares were due to begin trading, because of “major issues” that might cause it “not to meet the listing conditions or disclosure requirements.”

The IPO has also been suspended in Hong Kong, according to a statement from Ant Group, which referenced the meeting between Ma and Chinese officials as well as “recent changes” in regulations. In a statement on its official WeChat account, Ant Group apologized to investors for “any inconvenience caused by this development.”

The dual listing was set to raise $37 billion, making it the biggest share sale in history by a wide margin. Saudi state oil company Aramco holds the record for an IPO. It raised $29.4 billion when it issued shares on the Riyadh exchange last December.

Ant is an affiliate of Alibaba (BABA), which was also founded by Ma. The IPO would have valued it at more than $310 billion, making it worth more than major US investment banks such as Goldman Sachs (GS) and Morgan Stanley (MS). The company sells an array of financial products in China and its payments arm, Alipay, is the country’s biggest payments platform.

Shares in Alibaba (BABA) plunged as much as 9% in New York after the Ant IPO was suspended.

The move comes after the People’s Bank of China and three other financial regulators summoned Ma and two Ant Group executives for questioning on Monday. Just over a week ago, Ma publicly criticized Chinese regulators for stifling innovation by being too risk averse.

This is the first time that Chinese regulators have taken such drastic actions on the eve of a large IPO, senior geotechnology analyst at Eurasia Group Xiaomeng Lu told CNN Business.

“Jack Ma’s aggressive comments last weekend exacerbate the brewing conflict between large Chinese tech companies and powerful regulators,” Lu said in emailed comments. “Ant is likely to adjust its IPO valuation as a result of this intervention and delay its launch date.”

Duncan Clark, the author of “Alibaba: The House that Jack Ma Built” and chairman of investment advisory firm BDA China, said before the IPO was halted that Chinese regulators “want to put out statements that they’re the ones in charge, the ones in control. No regulator anywhere wants to be irrelevant,” he said.

On Monday, the China Banking and Insurance Regulatory Commission — one of the regulators that summoned the Ant executives — proposed new rules for online lenders. The rules could could mean that Ant would have to set aside more cash for the loans it facilitates and would place more credit risk on its balance sheet, according to Bernstein analyst Kevin Kwek.

While it’s not yet clear exactly why the Ant Group IPO was suspended, it could be an attempt by Beijing to remind Ma “who calls the shots,” Clark told CNN Business on Tuesday. Still, such a dramatic move so close to the listing date is surprising because it could damage Beijing’s drive to develop its capital markets, he added.

In September, China’s ruling Communist Party published an unusually frank set of guidelines for private businesses, stating that the private sector needs “politically sensible people” who will “firmly listen to the party and follow the party.” The directive indicates that President Xi Jinping is not afraid to take more overt measures to ensure that private companies support the Communist Party’s philosophies.

Ant Group said on Tuesday that it would stay in “close communications” with regulators and the Shanghai exchange.

“We will overcome the challenges and live up to the trust on the principles of: stable innovation; embrace of regulation; service to the real economy; and win-win cooperation,” the company said in its statement. “We will continue to serve small and micro businesses and ordinary citizens with our passion, professionalism and commitment for society.”

— Laura He, Steven Jiang, Hanna Zhang and Shanshan Wang contributed reporting.