S&P Global Ratings downgraded INC Research Holdings Inc.'s corporate credit rating to BB- from BB+.

The outlook is positive.

S&P said the downgrade reflects INC Research's merger with privately held inVentiv Health Inc., which will significantly increase the company's adjusted net debt leverage to the low-5x area at the end of 2017.

However, the rating agency also believes that the merger will boost INC Research's service offerings, customer base, and its therapeutic and geographic range.

The positive outlook reflects S&P Global's expectation for a slight decline in pro forma organic revenue for 2017 followed by a return to growth in 2018. The rating agency believes in the possibility of faster deleveraging over the next 12 months, due to operating outperformance and early paydown of debt.

S&P Global Ratings and S&P Global Market Intelligence are owned by S&P Global Inc.