The trailing 12-month U.S. high-yield corporate default rate increased to an estimated 2.8 percent in July from 2.7 percent in the prior month, according to Standard & Poor’s.

Three companies defaulted last month, bringing the total this year to 26, S&P analysts led by Diane Vazza in New York wrote in a report Wednesday. The trailing default rate for U.S. speculative-grade debt has risen from 2 percent at the end of 2011.

The extra yield investors demand to hold speculative-grade bonds rather than government debt declined to 616 basis points, or 6.16 percentage points, as of yesterday from this year’s high of 723 on June 5, according to the Bank of America Merrill Lynch U.S. High Yield Master II index.

High-yield, high-risk, or junk debt is rated below Baa3 by Moody’s Investors Service and lower than BBB- at S&P.