(Reuters) -Ratings agency S&P Global put a negative credit outlook on U.S. soft drinks giant Keurig Dr Pepper after the company announced Monday it will buy Dutch coffee group JDE Peet's.

In a Monday note accompanying their credit outlook downturn on the popular soda seller, S&P analysts highlighted the increased debt profile of Keurig following the announcement of its $18 billion takeover of Peet's.

The analysts noted Keurig's post-deal leverage will likely lie in the mid-to-high 5x range, well above its 4x leverage at the end of June.

Keurig announced early Monday morning its agreement to buy JDE Peet's in a deal offering a 20% premium to Peet's closing market price on Friday. Keurig expects to split the merged entity into two separate publicly traded U.S. companies - a firm focused on coffee operations and a second business focused on other beverages. 

S&P said it currently expects to officially downgrade Keurig's credit rating just one notch to BBB-, or the lower end of investment-grade, closer to the deal's closing date.

Analysts at S&P noted that they anticipate the combined company will lower its leverage back down to the low 4x range roughly two years after the deal closing, given their forecast it will "prioritize debt repayment, profit growth, and synergy realization such that credit metrics strengthen materially."