The issuer has set an initial guidance of around 7.125 percent for the planned issue, which could be priced as early as Thursday, one of the sources said on Thursday.
HSBC and UBS were hired to manage the issue, sources said.
In March, ICTSI sold $250 million of bonds due in 2020 at a yield of 7.375 percent, or 365.4 basis points over comparable U.S. Treasuries.