SINGAPORE - A GIC affiliate and a subsidiary of the Abu Dhabi Investment Authority (ADIA) are taking minority stakes in Pharmaceutical Product Development (PPD), a US-based contract research organization.

The deal, which values PPD at more than US$9 billion, is expected to close in the second quarter of this year, according to a news release from the company. The deal is also subject to regulatory approval.

Private equity firms Hellman & Friedman and The Carlyle Group, which took PPD private for US$3.9 billion in 2011, will maintain majority joint ownership of the company and invest equity from new funds into it, according to the release.

GIC, Singapore's sovereign wealth fund, and ADIA are both longtime investors in Carlyle and Hellman & Friedman.

PPD provides drug development and laboratory services for clients including pharmaceutical, biotechnology and medical device organizations and employs more than 19,000 in 47 countries.