America's companies, from Apple Inc. to Verizon Communications Inc., are saving about $700 billion in interest payments with the Federal Reserve's unprecedented stimulus.

Corporate bond yields over the past four years have fallen to an average of 4.6 percent from 6.14 percent in the five years before Lehman Brothers Holdings Inc.'s demise, a savings equal to $15.4 million annually per every $1 billion borrowed. Businesses took advantage of the Fed's largesse to lock in record low rates, extend maturities and raise cash by selling $5.16 trillion of bonds, data compiled by Bloomberg show.

"The stimulus was a huge saving grace in the economy overall," said J. Michael Schlotman, the chief financial officer at Cincinnati-based Kroger Co., the grocery store operator that estimates it's paying about $80 million less in interest than it would have pre-crisis. "It probably kept some businesses from failing because they were able to refinance their debt at lower interest payments."