Blackstone Inc. (NYSE:BX) is the frontrunner to win a roughly $17 billion portfolio of commercial-property loans from the Federal Deposit Insurance Corporation?s sale of Signature Bank debt, according to people familiar with the matter. Regulators seized the failed bank in March and have been marketing loans backed by retail, industrial, office and apartment buildings. FDIC officials are now in final discussions to declare Blackstone?s bid as bringing the lowest costs to the agency, some of the people said.