The Chinese owner of TikTok rejected Microsoft's offer to buy US operations for the popular video app, according to a statement from Microsoft released on Sunday.
The move left Oracle as the sole publicly known contender to purchase the American operations of TikTok.
"ByteDance let us know today they would not be selling TikTok's US operations to Microsoft," Microsoft wrote in the statement. "We are confident our proposal would have been good for TikTok's users, while protecting national security interests."
"To do this, we would have made significant changes to ensure the service met the highest standards for security, privacy, online safety, and combatting disinformation, and we made these principles clear in our August statement," the company continued in the announcement. "We look forward to seeing how the service evolves in these important areas."
It is unclear as to why Microsoft's bid was rejected. A representative from ByteDance did not immediately return Business Insider's request for comment.
President Donald Trump and a group of ByteDance's US investors have shown support for Oracle acquiring the US operations of TikTok, as the company has close ties with the Trump administration.
Sources involved in the acquisition talks told The New York Times that ByteDance has named Oracle as its "technology partner," though the company's bid has not been publicly accepted by the Chinese internet company.
The Journal and The Washington Post reported Sunday that Oracle was chosen in the deal for TikTok's American operations and will be named the app's "trusted tech partner" in the US, according to The Journal report.
President Donald Trump first set a deadline for the acquisition of TikTok's US operations for September 15, but since then, the president has issued two executive orders that have appeared to extend the deadline, first to September 20, then to mid-November.
The Wall Street Journal reported last Wednesday that ByteDance is in talks with the US government regarding "possible arrangements" that would avoid a "full sale" of TikTok's operations in the US following months of speculation about which American company would take over the app's American operations.
Paige Leskin contributed to this report.