SEC Closes Investigation into iBasis Stock Option Granting Practice; No Enforcement Action Recommended

BURLINTTON, MASS – 11/17/2009 – iBasis, Inc. (NASDAQ: IBAS), a KPN affiliate, today announced it has been notified by the staff of the Securities and Exchange Commission (SEC) that the agency has terminated its investigation into the companys past stock option grant practices, and that the staff does not intend to recommend any enforcement action against the company, or any of its current or former officers or directors.

About iBasis
Founded in 1996, iBasis (NASDAQ: IBAS) is a leading wholesale carrier of international long distance telephone calls and a provider of retail prepaid calling services and enhanced services for mobile operators. iBasis customers include KPN, KPN Mobile, E-Plus, BASE, TDC and many other large telecommunications carriers such as Verizon, Vodafone, China Mobile, China Unicom, IDT, Qwest, Skype, Telecom Italia, and Telefonica. The Company carried approximately 24 billion minutes of international voice traffic in 2008, placing the Company among the three largest carriers of international voice traffic in the world (1). The Company can be reached at its worldwide headquarters in Burlington, Mass., USA at +1 781-505-7500 or on the Internet at www.ibasis.com.

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Except for historical information, all of the expectations, plans and assumptions contained in the foregoing press release constitute forward-looking statements under Section 21E of the Securities Exchange Act of 1934 and involve risks and uncertainties that could cause results to vary materially. For a description of certain of these risks and uncertainties please read the Company’s most recent Annual Report on Form 10-K and other periodic and current reports, all of which are available atwww.sec.gov. Such forward-looking statements are only as of the date they are made.