Little more than a decade after consumers binged on inexpensive mortgages that helped bring on a global financial crisis, a new debt surge — this time by major corporations — threatens to unleash fresh turmoil. A decade of historically low interest rates has allowed companies to sell record amounts of bonds to investors, sending total U.S. corporate debt to nearly $10 trillion, or a record 47 percent of the overall economy. In recent weeks, the Federal Reserve, the International Monetary Fund and major institutional investors such as BlackRock and American Funds all have sounded the alarm about the mounting corporate obligations. The danger isn’t immediate. But some regulators and investors say the borrowing has gone on too long and could send financial markets plunging when the next recession hits, dealing the real economy a blow at a time when it already would be wobbling. Some of America’s best-known companies, […]