Across Mr. Trump’s business, he uses a similar web of privately held LLCs and other entities to house his assets—everything from real estate to a vintage carousel in Manhattan’s Central Park, according to a Wall Street Journal analysis of hundreds of pages of his corporate filings and personal financial disclosures. Fifteen entities, for example, are used to hold his interests in two airplanes and three helicopters.

Roughly half—at least $304 million—of the revenue Mr. Trump reported in a federal financial disclosure form earlier this year came from assets held in 96 different LLCs, according to the Journal’s analysis. Those assets include a skyscraper at 40 Wall Street in Manhattan and the Mar-a-Lago Club in Palm Beach, Fla…

Unlike publicly traded companies, Delaware LLCs don’t have to publish any financial information or even disclose the identity of the owner. In addition, the most a member of an LLC can lose if the company fails is normally the amount he or she has invested in that company—unless there is a personal guarantee.

None of the 96 LLCs examined by the Journal appear to regularly release audited financial statements. That opacity—compounded by Mr. Trump’s decision to break with decades of precedent by declining to release his tax returns—makes it impossible to gauge the full extent of potential conflicts between his business interests and presidential role.