Twitter recently was in talks to acquire Clubhouse, the heavily hyped live-audio social media app, in a deal worth $4 billion, Bloomberg reported, citing anonymous sources.

Twitter’s overture came even as it has been developing a similar feature called Spaces. According to the report, the discussions between the two companies have since ended.

Asked about the report, a Twitter rep said, “We don’t comment on rumors or speculation.” Clubhouse didn’t immediately respond to a request for comment.

Clubhouse, launched in April 2020, has had more than 15 million app installs to date, according to research firm Sensor Tower. The service lets users host invitation-only live audio discussions with hundreds or even thousands of users. “Go online anytime to chat with the people you follow, or hop in as a listener and hear what others are talking about,” reads the app’s iOS description.

At this point, Clubhouse is in talks to raise funding from investors that would value the startup at about $4 billion, per Bloomberg. The San Francisco company, whose legal name is Alpha Exploration Co., has raised $110 million from investors including VC firms Andreessen Horowitz and Kortschak Investments, according to Crunchbase.

Meanwhile, Twitter has been testing out its Spaces, which lets small groups of people talk privately with each other in real time (like on a conference call). The company has said it plans to open Twitter Spaces to all users later in April.

As of the end of 2020, Twitter reported $7.47 billion in cash and equivalents on its balance sheet.

Separately, last week Spotify announced the acquisition of Betty Labs, the creators of Locker Room, a live audio app focused on sports talk, and said it plans to launch a range of new live and interactive programming in the next few months.