Company offers increased opportunities for efficiency and growth through thexchange

NEW BRUNSWICK, N.J., May 22, 2008 /PRNewswire-FirstCall via COMTEX News Network/ -- Arbinet-thexchange,
Inc. (Nasdaq: ARBX), the robust transaction platform for buying and selling
voice and IP telecommunications capacity, announced today that it has
surpassed the 1,000 Member mark during the first quarter of 2008. The company
also indicated that March 2008 was the highest revenue month since its
inception.

Arbinet, which now has 1,045 Members on the thexchange, experienced an
increase in Membership due to the company's expansion in many emerging
markets. Recently Arbinet announced its increased presence in the Middle East
market, signing on a number of new customers and opening an office in Beirut
to handle the demands of service providers in the region. In addition, the
company has experienced membership growth in Asia, Africa and Latin America.

"Arbinet's increased membership base and continuous global expansion
enable us to offer more choices and greater connectivity," said William
Freeman, president and CEO, Arbinet. "Our solutions, coupled with our
intelligent platform and routing expertise, empower Members to manage their
operations and grow their businesses more effectively."

As Arbinet expands its presence globally, the company continues to attract
buyers and sellers to its marketplace with a range of services that enhance
business choices and opportunities for its Members. Arbinet's flexible,
scalable solutions and managed services enable telecommunications providers to
improve business efficiency and excel in an increasingly demanding and
competitive market. This 1,000 Member milestone is a result of the
outstanding solutions and services Arbinet continues to provide to Members
around the world.

About Arbinet

Arbinet is a leading provider of innovative voice and IP solutions
empowering communications companies to create the most efficient and valuable
global interconnections. Arbinet offers the greatest flexibility in global
scale, platform intelligence, and managed solutions to achieve commercial
efficiency and interconnection simplicity.

Arbinet manages business relationships, back office operations and call
routing for Members who route through Arbinet approximately 2% of the world's
international voice traffic to over 1,300 destinations worldwide. These
Members include fixed line, mobile, wholesale and VoIP carriers as well as
calling card, ISPs and content providers around the world who buy and sell
voice and IP telecommunications capacity and content. For more information
about Arbinet's solutions, visit www.arbinet.com

Forward-Looking Statements

This press release contains forward-looking statements regarding
anticipated future revenues, growth, capital expenditures, management's future
expansion plans, expected product and service developments or enhancements,
and future operating results. Such forward-looking statements may be
identified by, among other things, the use of forward-looking terminology such
as: "believes," "expects," "may," "will," "should" or "anticipates," or the
negative thereof or other variations thereon or comparable terminology, or by
discussions of strategy that involve risks and uncertainties. Various
important risks and uncertainties may cause Arbinet's actual results to differ
materially from the results indicated by these forward-looking statements,
including, without limitation: the ability of Arbinet to effectively divest
Broad Street Digital Limited; members (in particular, significant trading
members) not trading on our exchange or utilizing our new and additional
services (including DirectAxcess(SM), PrivateExchange(SM), AssuredAxcess(SM)
and PeeringSolutions(SM)); continued volatility in the volume and mix of
trading activity; our uncertain and long member enrollment cycle; the failure
to manage our credit risk; failure to manage our growth; pricing pressure;
investment in our management team and investments in our personnel; regulatory
uncertainty; system failures, human error and security breaches that could
cause Arbinet to lose members and expose it to liability; and Arbinet's
ability to obtain and enforce patent protection for our methods and
technologies. For a further list and description of the risks and
uncertainties the Company faces, please refer to Part I, Item 1A of the
Company's Annual Report on Form 10-K, filed with the Securities and Exchange
Commission on March 17, 2008, and other filings that have been filed with the
Securities and Exchange Commission. Arbinet assumes no obligation to update
any forward-looking statements, whether as a result of new information, future
events or otherwise and such statements are current only as of the date they
are made.