Blackstone Group LP, the world’s largest private-equity investor in real estate, is unlikely to lead a takeover offer for Macerich Co., Bloomberg reported yesterday. Macerich, the third-biggest publicly traded U.S. mall owner, earlier Tuesday rejected a $16 billion takeover offer from Simon Property Group Inc., the largest company in the industry. One newsletter reported last week that Blackstone may be working with other investors to put together a group bid for the Santa Monica, Calif.-based real estate investment trust. Blackstone had invested with partners in 2010 to bring General Growth Properties Inc. out of bankruptcy. It sold its shares at a profit three years later. The New York-based firm has also been expanding in high-quality, well-leased real estate through a new fund to acquire so-called core-plus properties.