Shares of Pharmaceutical Product Development, Inc. (Nasdaq: PPDI) were up as much as 27 percent from Friday’s closing price in morning trading on Monday after it was announced that PPD entered into a definitive merger agreement under which it will be acquired by affiliates of The Carlyle Group and Hellman & Friedman in an all-cash transaction valued at $3.9 billion, after which PPD will be a private company, an October 3 press release stated.

Shares of PPDI touched a high of $32.63, up from Friday’s closing price of $25.66.

Under the terms of the merger agreement, Carlyle and Hellman & Friedman will acquire the outstanding common shares of PPD for $33.25 per share in cash. This represents a premium of 29.6 percent over PPD’s closing price on September 30, 2011.

“The sale of PPD to The Carlyle Group and Hellman & Friedman provides an attractive return for our shareholders, while also ensuring a secure foundation and commitment to investment, innovation and excellence for PPD clients and employees as the company builds on its 25-year history of success,” said Fred Eshelman, founder and executive chairman of Pharmaceutical Product Development, Inc. in an October 3 press release.

Pharmaceutical product Development, Inc. is a leading global contract research organization that provides drug discovery, development and lifecycle management services for clients and partners including pharmaceutical, biotechnology, medical device, academic and government organizations.

The transaction is currently expected to close in the fourth quarter of 2011. Following completion of the transaction, PPD will become a privately held company and its stock will no longer trade on Nasdaq. PPD noted that, in light of the proposed transaction, it will not host a conference call to discuss financial results for the third quarter of 2011.