Alibaba Group Holding Ltd. unit Alibaba Cloud Computing is developing an operating system for mobile phones that it aims to release in the third quarter, a person close to the situation said Monday, as a range of companies battle to provide the core software used on smartphones. The Alibaba offering will add to the competition in China for Google Inc.’s (GOOG) Android operating system, Apple Inc.’s (AAPL) iPhone smartphones and Microsoft Corp.’s (MSFT) Windows Phone platform. The move also seems to mark a new direction for Alibaba Group, as the company has made software before but is best known for operating online-commerce websites. The Alibaba operating system will offer “cloud-based” services such as applications that the user can access on a remote server instead of downloading them to the phone, the person said. Users of iPhone and Android handsets usually download apps to their devices.