Microsoft has said that its offer to buy the US operations of hugely popular video-sharing app TikTok has been rejected, paving the way for Oracle to make a last-minute bid.
US President Donald Trump gave a 15 September deadline for the Chinese-owned app to sell or shut down.
The Trump administration claims TikTok and other Chinese apps are national security threats.
Microsoft and Oracle led the race to buy TikTok from Chinese firm ByteDance.
The Wall Street Journal and Reuters have reported that Oracle had won the bidding war, citing people familiar with the matter.
A TikTok spokesperson told the BBC the firm was "not commenting on either the Microsoft development nor the Oracle speculation".
On Sunday Microsoft announced that “ByteDance let us know today they would not be selling TikTok’s US operations to Microsoft. We are confident our proposal would have been good for TikTok’s users, while protecting national security interests.”
“We look forward to seeing how the service evolves in these important areas,” its statement added.
This paves the way for Oracle, who Mr Trump said would be "a great company" to take over TikTok's US operations last month.
Oracle's chairman Larry Ellison is a supporter of Mr Trump and held a fundraising event for him in February.