Twitter Inc. said it agreed to sell MoPub, the company’s advertising platform for third-party mobile apps, to AppLovin Corp. for US$1.05 billion in cash.

The social-media company acquired MoPub in September 2013 for US$350 million as a way to expand its advertising business and help place ads inside of other apps, as well as build an auction for Twitter’s own ad product. 

Twitter executives said that selling MoPub will allow the company to better focus on building advertising products for its service. 

“The sale of MoPub positions us to concentrate more of our efforts on the massive potential for ads on our website and in our apps,” Chief Financial Officer Ned Segal said Wednesday in a statement.