Blackstone Inc. (NYSE:BX) is planning to file as soon as next month for an initial public offering of its Indian shopping mall portfolio that could raise about $500 million, people familiar with the matter said. The private equity firm has been interviewing advisers for the Mumbai listing of a real estate investment trust, according to the people, who asked not to be identified because the information is private. Blackstone's Indian retail portfolio, which is held through its Nexus Malls unit, could be valued at about $2.5 billion, the people said.

The REIT could be listed as soon as 2023, they said. Preparations are at an early stage, and details of the listing could change, the people said. A company representative declined to comment.