PharmaNet Development Group stockholders have another week to tender their shares as part of the contract research organization (CRO)’s pending acquisition by private equity firm JLL Partners.

JLL Partners extended the expiration date for its previously announced tender offer for all of the outstanding shares of PharmaNet’s common stock. The tender offer, which had been scheduled to expire at midnight March 12, 2009, will now expire at midnight (EDT) on March 19, 2009.

As of yesterday’s initial deadline, a total of approximately 17,286,075 shares representing approximately 87.32% of the outstanding shares of common stock had been validly tendered and not withdrawn (in addition to 4,817,627 shares tendered under guaranteed delivery procedures).

PharmaNet signed a definitive merger agreement with JLL Partners earlier this month, a $250-million deal that will make the new public CRO a private company.