Blackstone Group LP will follow KKR and Ares Management in converting into a corporation. : (Bloomberg)—Blackstone Group LP plans to convert to a corporation from a publicly traded partnership, a step that opens up the stock for inclusion in indexes, after watching two rivals benefit from the move. The shares jumped in early trading. Changing the company’s structure will increase the firm’s “ability to reach a dramatically larger audience,” Chief Executive Officer Stephen Schwarzman, said Thursday in a Bloomberg Television interview. “We’d handicapped ourselves by our corporate form,” he said.