The deal to merge Raleigh clinical research organization PRA International with Pennsylvania CRO ReSearch Pharmaceutical Services will be financed in part by at least $375 million in debt.

When the merger was announced in July, PRA’s private equity owner KKR (NYSE:KKR) did not disclose any financial terms of the deal. But on Wednesday PRA said that another unit, Pinnacle Merger Sub, Inc., will offer $375 million a proposed private offering of senior notes. The proceeds would be used to finance KKR’s CRO transactions. PRA said Pinnacle will be merged into PRA when the offering is consummated.

KKR announced in late July that it was acquiring RPS and planned to merge that CRO with PRA to form a larger, global provider of pharmaceutical services. The combined company will be led by current PRA CEO Colin Shannon; RPS is slated to operate independently as the “Strategic Solutions Division” of PRA. It was the second major transaction announced this summer involving PRA. In June, KKR acquired PRA for an undisclosed sum.

PRA said Wednesday that net proceeds from the offering will be used to finance in part the acquisition of PRA and RPS by KKR; the repayment of existing debt of PRA and RPS; and the payment of fees and expenses in connection with those transactions. The notes, which will be guaranteed on a senior basis by all of PRA’s existing and future subsidiaries, will be due in 2023.

While KKR has been tight-lipped about the financial details of its CRO acquisitions, Bloomberg News reported in August that KKR is seeking $950 million in loans to support the buyout and merger of RPS. Bloomberg cited an unnamed “person with knowledge of the transaction.”

Bloomberg’s source said that UBS, Jefferies Group Inc., Credit Suise Group, KKR’s lending arm and Citigroup are arranging the financing for the recent CRO deals, which includes a five-year $125 million revolving line of credit and an $825 million first-lien term price that matures in seven years.

According to data compiled by Bloomberg, KKR has invested more than $9 billion in health care globally since 1995, including its 2006 acquisition with Bain Capital and Merrill Lynch & Co. of HCA Inc. for $32 billion.

KKR has said that it expects to close the CRO transactions in the third quarter.