US tech firm Oracle is the sole remaining bidder ahead of a looming deadline for the Chinese-owned video app to sell or shut down its US operations as Microsoft said that its offer to buy TikTok was rejected.
The Wall Street Journal and New York Times reported that Oracle had won the bidding war, citing people familiar with the deal.
The Oracle bid would next need approval from the White House and committee on Foreign Investment in the US, a source told the Journal, with both parties under the belief it would meet US data security concerns.
TikTok has been at the centre of a diplomatic storm between Washington and Beijing, and president Donald Trump has given Americans a deadline to stop doing business with TikTok's Chinese parent company ByteDance -- effectively compelling a sale of the app to a US company.
Microsoft had indicated at the beginning of August that it was interested in acquiring TikTok's US operations, but said Sunday(13) that bid had been rejected.
"ByteDance let us know today they would not be selling TikTok's US operations to Microsoft," the US tech giant said in a statement.
"We are confident our proposal would have been good for TikTok's users, while protecting national security interests," it added.
A deal with Microsoft could also have included Walmart, which joined forces with the tech giant in negotiations.
In early August, Trump issued an executive order stating that if a purchase agreement were not reached by September 20, the platform would have to close in the US.
Trump claims that TikTok could be used by China to track the locations of federal employees, build dossiers on people for blackmail and conduct corporate espionage.
In late August China's commerce ministry published new rules potentially making it more difficult for ByteDance to sell TikTok to a US entity by adding "civilian use" to a list of technologies that are restricted for export.
ByteDance had vowed to "strictly abide" by new export rules.
Downloaded 175 million times in the US, TikTok is used by as many as a billion people worldwide to make quirky, short-form videos on their cellphones. It has repeatedly denied sharing data with Beijing.
TikTok meanwhile has filed a lawsuit challenging the crackdown by the US government, contending that Trump's order was a misuse of the International Emergency Economic Powers Act because the platform is not "an unusual and extraordinary threat."
Controversially Trump has demanded that the US government get a cut of any deal, which critics contend appears unconstitutional and akin to extortion.
Washington has accused other Chinese tech firms such as Huawei of working in the interests of the Chinese Communist Party.